@Override
 public PyType getReferenceType(
     @NotNull PsiElement referenceTarget, TypeEvalContext context, @Nullable PsiElement anchor) {
   if (referenceTarget instanceof PyTargetExpression) {
     final PyTargetExpression target = (PyTargetExpression) referenceTarget;
     if (context.maySwitchToAST(target)) {
       // XXX: Requires switching from stub to AST
       final PyAnnotation annotation = target.getAnnotation();
       if (annotation != null) {
         final PyExpression value = annotation.getValue();
         if (value != null) {
           return getType(value, new Context(context));
         }
         return null;
       }
     }
     final String comment = target.getTypeCommentAnnotation();
     if (comment != null) {
       final PyType type = getStringBasedType(comment, referenceTarget, new Context(context));
       if (type instanceof PyTupleType) {
         final PyTupleExpression tupleExpr =
             PsiTreeUtil.getParentOfType(target, PyTupleExpression.class);
         if (tupleExpr != null) {
           return PyTypeChecker.getTargetTypeFromTupleAssignment(
               target, tupleExpr, (PyTupleType) type);
         }
       }
       return type;
     }
   }
   return null;
 }
 @Nullable
 @Override
 public Ref<PyType> getReturnType(@NotNull PyCallable callable, @NotNull TypeEvalContext context) {
   if (callable instanceof PyFunction) {
     final PyFunction function = (PyFunction) callable;
     final PyAnnotation annotation = function.getAnnotation();
     if (annotation != null) {
       // XXX: Requires switching from stub to AST
       final PyExpression value = annotation.getValue();
       if (value != null) {
         final PyType type = getType(value, new Context(context));
         return type != null ? Ref.create(type) : null;
       }
     }
     final PyType constructorType = getGenericConstructorType(function, new Context(context));
     if (constructorType != null) {
       return Ref.create(constructorType);
     }
     final String comment = function.getTypeCommentAnnotation();
     if (comment != null) {
       final PyTypeParser.ParseResult result =
           PyTypeParser.parsePep484FunctionTypeComment(callable, comment);
       final PyCallableType funcType = as(result.getType(), PyCallableType.class);
       if (funcType != null) {
         return Ref.create(funcType.getReturnType(context));
       }
     }
   }
   return null;
 }
  @Nullable
  public Ref<PyType> getParameterType(
      @NotNull PyNamedParameter param, @NotNull PyFunction func, @NotNull TypeEvalContext context) {
    final PyAnnotation annotation = param.getAnnotation();
    if (annotation != null) {
      // XXX: Requires switching from stub to AST
      final PyExpression value = annotation.getValue();
      if (value != null) {
        final PyType type = getType(value, new Context(context));
        if (type != null) {
          final PyType optionalType = getOptionalTypeFromDefaultNone(param, type, context);
          return Ref.create(optionalType != null ? optionalType : type);
        }
      }
    }

    final String paramComment = param.getTypeCommentAnnotation();
    if (paramComment != null) {
      return Ref.create(getStringBasedType(paramComment, param, new Context(context)));
    }

    final String comment = func.getTypeCommentAnnotation();
    if (comment != null) {
      final PyTypeParser.ParseResult result =
          PyTypeParser.parsePep484FunctionTypeComment(param, comment);
      final PyCallableType functionType = as(result.getType(), PyCallableType.class);
      if (functionType != null) {
        final List<PyCallableParameter> paramTypes = functionType.getParameters(context);
        // Function annotation of kind (...) -> Type
        if (paramTypes == null) {
          return Ref.create();
        }
        final PyParameter[] funcParams = func.getParameterList().getParameters();
        final int startOffset = omitFirstParamInTypeComment(func) ? 1 : 0;
        for (int paramIndex = 0; paramIndex < funcParams.length; paramIndex++) {
          if (funcParams[paramIndex] == param) {
            final int typeIndex = paramIndex - startOffset;
            if (typeIndex >= 0 && typeIndex < paramTypes.size()) {
              return Ref.create(paramTypes.get(typeIndex).getType(context));
            }
            break;
          }
        }
      }
    }
    return null;
  }