diff --git a/pkg/dart2wasm/analysis_options.yaml b/pkg/dart2wasm/analysis_options.yaml
index c54ed7392f1..bb01371e023 100644
--- a/pkg/dart2wasm/analysis_options.yaml
+++ b/pkg/dart2wasm/analysis_options.yaml
@@ -10,6 +10,7 @@ analyzer:
 
   exclude:
     - test/ir_tests/*.dart
+    - test/deferred_loading/partition_tests/*.dart
 
 linter:
   rules:
diff --git a/pkg/dart2wasm/lib/deferred_load/partition.dart b/pkg/dart2wasm/lib/deferred_load/partition.dart
index ee79fa53231..181d17accd5 100644
--- a/pkg/dart2wasm/lib/deferred_load/partition.dart
+++ b/pkg/dart2wasm/lib/deferred_load/partition.dart
@@ -255,17 +255,22 @@ class _Algorithm {
     final namedNodes = ProgramSplitBuilder();
     final orderNodes = <OrderNode>[];
 
+    final filteredUserConstraints = _filterUserConstraints(
+      userConstraints,
+      allDeferredImportsIncludingRoot,
+    );
+
     // If user provided constraints, initialize from them.
     final existingNames = <String, NamedNode>{};
-    if (userConstraints != null) {
-      for (final named in userConstraints!.named) {
+    if (filteredUserConstraints != null) {
+      for (final named in filteredUserConstraints.named) {
         if (named is ReferenceNode) {
           final import = UriAndPrefix(named.uri, named.prefix).toString();
           existingNames[import] = named;
         }
         namedNodes.namedNodes[named.name] = named;
       }
-      for (final ordered in userConstraints!.ordered) {
+      for (final ordered in filteredUserConstraints.ordered) {
         orderNodes.add(ordered);
       }
     }
@@ -298,6 +303,94 @@ class _Algorithm {
     ).build(allDeferredImportsIncludingRoot);
   }
 
+  ConstraintData? _filterUserConstraints(
+    ConstraintData? userConstraints,
+    Set<LibraryDependency> allDeferredImportsIncludingRoot,
+  ) {
+    if (userConstraints == null) return null;
+
+    /// The set of all prefixes (even unreachable ones).
+    final allPrefixNames = <String>{
+      for (final library in component.libraries)
+        for (final import in library.dependencies)
+          if (import.isDeferred) import.uriPrefix,
+    };
+
+    /// The set of reachable prefixes.
+    final validImportPrefixes = allDeferredImportsIncludingRoot
+        .map((d) => d.uriPrefix)
+        .toSet();
+
+    final newNamedNodes = <NamedNode, NamedNode>{};
+
+    // Find [ReferenceNode]s that exist.
+    for (final NamedNode node in userConstraints.named) {
+      if (node is ReferenceNode) {
+        final importPrefix = UriAndPrefix(node.uri, node.prefix).toString();
+        if (validImportPrefixes.contains(importPrefix)) {
+          newNamedNodes[node] = node;
+          continue;
+        }
+        if (!allPrefixNames.contains(importPrefix)) {
+          throw StateError('The library $importPrefix is not known.');
+        }
+        // The [importPrefix] is in the Kernel AST but unreachable. This can
+        // happen due to RTA+TFA leaving unreachable code behind. We therefore
+        // prune this node and simplify or remove depending constraint nodes
+        // below.
+      }
+    }
+
+    // Prune or remove [CombinerNode]s.
+    for (final NamedNode node in userConstraints.named) {
+      if (node is CombinerNode) {
+        final Set<ReferenceNode> remaining = node.nodes
+            .where(newNamedNodes.containsKey)
+            .toSet();
+        if (remaining.isEmpty) continue;
+        if (node.type == CombinerType.and &&
+            remaining.length < node.nodes.length) {
+          continue;
+        }
+        if (remaining.length == 1) {
+          newNamedNodes[node] = remaining.first;
+        } else {
+          newNamedNodes[node] = CombinerNode(node.name, node.type, remaining);
+        }
+      }
+    }
+
+    // Filter/prune [OrderNode]s.
+    final newOrderNodes = <OrderNode>[];
+    for (final node in userConstraints.ordered) {
+      if (node is RelativeOrderNode) {
+        final predecessor = newNamedNodes[node.predecessor];
+        final successor = newNamedNodes[node.successor];
+        if (predecessor != null && successor != null) {
+          newOrderNodes.add(
+            RelativeOrderNode(predecessor: predecessor, successor: successor),
+          );
+        }
+        continue;
+      }
+      if (node is FuseNode) {
+        final newNodes = <NamedNode>{};
+        for (final node in node.nodes) {
+          final newNode = newNamedNodes[node];
+          if (newNode == null) continue;
+          newNodes.add(newNode);
+        }
+        if (newNodes.length >= 2) {
+          newOrderNodes.add(FuseNode(newNodes));
+        }
+        continue;
+      }
+      throw StateError('Unknown order node $node.');
+    }
+
+    return ConstraintData(newNamedNodes.values.toList(), newOrderNodes);
+  }
+
   void collectDependencies(Set<Reference> roots) {
     for (final reference in roots) {
       ensureReferenceDependencies(reference);
diff --git a/pkg/dart2wasm/test/deferred_loading/partition_test.dart b/pkg/dart2wasm/test/deferred_loading/partition_test.dart
index 7080f8f879f..89fa1bc202c 100644
--- a/pkg/dart2wasm/test/deferred_loading/partition_test.dart
+++ b/pkg/dart2wasm/test/deferred_loading/partition_test.dart
@@ -38,15 +38,36 @@ Future runDart2wasmTests() async {
       .toList();
   for (final mainFile in tests) {
     final mainFilePath = mainFile.path;
-    final defaultSplitExpectationFile =
-        '${mainFilePath.substring(0, mainFilePath.length - '.dart'.length)}.default.txt';
+    final mainFileBasePath = mainFilePath.substring(
+      0,
+      mainFilePath.length - '.dart'.length,
+    );
 
-    // Test without constraints.
+    // Generate a partitioning without constraints under
+    // `<testname>.default.txt`.
     await testPartitionExpectation(
       mainFilePath,
       null,
-      defaultSplitExpectationFile,
+      '$mainFileBasePath.default.txt',
     );
+
+    // If the `<testname>.constraints.json` exists generate a partitioining with
+    // constraints under `<testname>.constraints.txt`.
+    final jsonConstraintsFile = File('$mainFileBasePath.constraints.json');
+    if (jsonConstraintsFile.existsSync()) {
+      final constraintsJsonString = jsonConstraintsFile
+          .readAsStringSync()
+          .replaceAll(
+            '\${SDK_ROOT}',
+            Directory.current.absolute.uri.toString(),
+          );
+      final constraints = Parser().read(constraintsJsonString);
+      await testPartitionExpectation(
+        mainFilePath,
+        constraints,
+        '$mainFileBasePath.constraints.txt',
+      );
+    }
   }
 }
 
diff --git a/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.json b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.json
new file mode 100644
index 00000000000..826d81067eb
--- /dev/null
+++ b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.json
@@ -0,0 +1,90 @@
+[
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_1",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_1"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_2",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_2"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrDead",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrDead"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_1",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_1"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_2",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_2"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndDead",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndDead"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_1",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_1"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_2",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_2"
+  },
+  {
+    "type": "reference",
+    "name": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseDead",
+    "import": "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseDead"
+  },
+  {
+    "type": "or",
+    "name": "or_with_dead",
+    "nodes": [
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_1",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrAlive_2",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#OrDead"
+    ]
+  },
+  {
+    "type": "and",
+    "name": "and_with_dead",
+    "nodes": [
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_1",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndAlive_2",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#AndDead"
+    ]
+  },
+  {
+    "type": "fuse",
+    "nodes": [
+      "or_with_dead",
+      "and_with_dead",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_1",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseAlive_2",
+      "${SDK_ROOT}pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart#FuseDead"
+    ]
+  }
+]
diff --git a/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.txt b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.txt
new file mode 100644
index 00000000000..805d7277b5e
--- /dev/null
+++ b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.constraints.txt
@@ -0,0 +1,75 @@
+Part 0
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_2
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testOr
+  Constants
+
+Part 1
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testAnd
+  Constants
+
+Part 2
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_2
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testFuse
+  Constants
+
+Part 3
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::orTest_alive_1
+  Constants
+     - StringConstant("orTest_alive_1")
+
+Part 4
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::orTest_alive_2
+  Constants
+     - StringConstant("orTest_alive_2")
+
+Part 5
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_1
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::andTest_alive_1
+  Constants
+     - StringConstant("andTest_alive_1")
+
+Part 6
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::andTest_alive_2
+  Constants
+     - StringConstant("andTest_alive_2")
+
+Part 7
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_2
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::fuseTest_alive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::fuseTest_alive_2
+  Constants
+     - StringConstant("fuseTest_alive_1")
+     - StringConstant("fuseTest_alive_2")
diff --git a/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart
new file mode 100644
index 00000000000..5948d9f68c4
--- /dev/null
+++ b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart
@@ -0,0 +1,102 @@
+// Copyright (c) 2026, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Or node
+import '' deferred as OrAlive;
+import '' deferred as OrAlive_1;
+import '' deferred as OrAlive_2;
+import '' deferred as OrDead;
+
+// And node
+import '' deferred as AndAlive;
+import '' deferred as AndAlive_1;
+import '' deferred as AndAlive_2;
+import '' deferred as AndDead;
+
+// Fuse node
+import '' deferred as FuseAlive;
+import '' deferred as FuseAlive_1;
+import '' deferred as FuseAlive_2;
+import '' deferred as FuseDead;
+
+void main() async {
+  print('main');
+  switch (opaqueInt) {
+    case 1:
+      await OrAlive.loadLibrary();
+      await OrAlive.testOr();
+      break;
+    case 2:
+      await AndAlive.loadLibrary();
+      await AndAlive.testAnd();
+      break;
+    case 3:
+      await FuseAlive.loadLibrary();
+      await FuseAlive.testFuse();
+      break;
+  }
+}
+
+Future testOr() async {
+  switch (opaqueInt) {
+    case 1:
+      await OrAlive_1.loadLibrary();
+      OrAlive_1.orTest_alive_1();
+      break;
+    case 2:
+      await OrAlive_2.loadLibrary();
+      OrAlive_2.orTest_alive_2();
+      break;
+    default:
+      if (alwaysFalse) {
+        await OrDead.loadLibrary();
+        OrDead.orTest_dead();
+      }
+      break;
+  }
+}
+
+Future testAnd() async {
+  for (int i = 0; i < 3; ++i) {
+    if (i == 0) {
+      await AndAlive_1.loadLibrary();
+      AndAlive_1.andTest_alive_1();
+    } else if (i == 1) {
+      await AndAlive_2.loadLibrary();
+      AndAlive_2.andTest_alive_2();
+    } else {
+      if (!alwaysTrue) {
+        await AndDead.loadLibrary();
+        AndDead.andTest_dead();
+      }
+    }
+  }
+}
+
+Future testFuse() async {
+  await FuseAlive_1.loadLibrary();
+  FuseAlive_1.fuseTest_alive_1();
+  await FuseAlive_2.loadLibrary();
+  FuseAlive_2.fuseTest_alive_2();
+  if (alwaysFalse) {
+    await FuseDead.loadLibrary();
+    FuseDead.fuseTest_dead();
+  }
+}
+
+void orTest_alive_1() => print('orTest_alive_1');
+void orTest_alive_2() => print('orTest_alive_2');
+void orTest_dead() => print('orTest_dead');
+
+void andTest_alive_1() => print('andTest_alive_1');
+void andTest_alive_2() => print('andTest_alive_2');
+void andTest_dead() => print('andTest_dead');
+
+void fuseTest_alive_1() => print('fuseTest_alive_1');
+void fuseTest_alive_2() => print('fuseTest_alive_2');
+void fuseTest_dead() => print('fuseTest_dead');
+
+int get opaqueInt => int.parse('1');
+bool get alwaysTrue => true;
+bool get alwaysFalse => false;
diff --git a/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.default.txt b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.default.txt
new file mode 100644
index 00000000000..0fc04876eaa
--- /dev/null
+++ b/pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.default.txt
@@ -0,0 +1,74 @@
+Part 0
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testOr
+  Constants
+
+Part 1
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testAnd
+  Constants
+
+Part 2
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_1
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::testFuse
+  Constants
+
+Part 3
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_1
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::orTest_alive_1
+  Constants
+     - StringConstant("orTest_alive_1")
+
+Part 4
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: OrAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::orTest_alive_2
+  Constants
+     - StringConstant("orTest_alive_2")
+
+Part 5
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_1
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::andTest_alive_1
+  Constants
+     - StringConstant("andTest_alive_1")
+
+Part 6
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: AndAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::andTest_alive_2
+  Constants
+     - StringConstant("andTest_alive_2")
+
+Part 7
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_1
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::fuseTest_alive_1
+  Constants
+     - StringConstant("fuseTest_alive_1")
+
+Part 8
+  ImportSet
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart prefix: FuseAlive_2
+  References
+     - pkg/dart2wasm/test/deferred_loading/partition_tests/dead_constraint.dart::@methods::fuseTest_alive_2
+  Constants
+     - StringConstant("fuseTest_alive_2")