anchor.diff:  }
   
   class CompileFactoryMetadata
  -    implements CompileIdentifierMetadata, CompileMetadataWithIdentifier {
  +    implements
  +        CompileIdentifierMetadata<Function>,
  +        CompileMetadataWithIdentifier {
     Function runtime;
     Function runtimeCallback;
     String name;
  
positive.code:   return _COMPILE_METADATA_FROM_JSON[data["class"]](data);
  }
  
  class CompileIdentifierMetadata implements CompileMetadataWithIdentifier {
    String name;
    String prefix;
    String moduleUrl;
  
negative.code:  * Metadata regarding compilation of a type.
   */
  class CompileTypeMetadata
      implements CompileIdentifierMetadata<Type>, CompileMetadataWithType {
    Type runtime;
    Function runtimeCallback;
    String name;
  