anchor.diff:      if (!accessorElement.isSynthetic &&
           accessorElement.isGetter &&
           !accessorElement.isStatic &&
  -        accessorElement.hasImplicitReturnType &&
  -        _getReturnType(accessorElement).isDynamic) {
  +        accessorElement.hasImplicitReturnType) {
         List<ExecutableElement> overriddenGetters = inheritanceManager
             .lookupOverrides(
                 accessorElement.enclosingElement, accessorElement.name);
  
positive.code:     //
      // Infer the return type.
      //
      if (methodElement.hasImplicitReturnType &&
          _getReturnType(methodElement).isDynamic) {
        overriddenMethods = inheritanceManager.lookupOverrides(
            methodElement.enclosingElement, methodElement.name);
        if (overriddenMethods.isEmpty || !_onlyMethods(overriddenMethods)) {
  
negative.code:  * instance methods within a single compilation unit.
   */
  class InstanceMemberInferrer {
    /**
     * The type provider used to look up types.
     */
  