private static Collection<ClassDescriptor> getClassOrObjectDescriptorsByFqName(
      NamespaceDescriptor packageDescriptor, FqName path, boolean includeObjectDeclarations) {
    if (path.isRoot()) {
      return Collections.emptyList();
    }

    Collection<JetScope> scopes = Arrays.asList(packageDescriptor.getMemberScope());

    List<Name> names = path.pathSegments();
    if (names.size() > 1) {
      for (Name subName : path.pathSegments().subList(0, names.size() - 1)) {
        Collection<JetScope> tempScopes = Lists.newArrayList();
        for (JetScope scope : scopes) {
          ClassifierDescriptor classifier = scope.getClassifier(subName);
          if (classifier instanceof ClassDescriptorBase) {
            ClassDescriptorBase classDescriptor = (ClassDescriptorBase) classifier;
            tempScopes.add(classDescriptor.getUnsubstitutedInnerClassesScope());
          }
        }
        scopes = tempScopes;
      }
    }

    Name shortName = path.shortName();
    Collection<ClassDescriptor> resultClassifierDescriptors = Lists.newArrayList();
    for (JetScope scope : scopes) {
      ClassifierDescriptor classifier = scope.getClassifier(shortName);
      if (classifier instanceof ClassDescriptor) {
        resultClassifierDescriptors.add((ClassDescriptor) classifier);
      }
      if (includeObjectDeclarations) {
        ClassDescriptor objectDescriptor = scope.getObjectDescriptor(shortName);
        if (objectDescriptor != null) {
          resultClassifierDescriptors.add(objectDescriptor);
        }
      }
    }

    return resultClassifierDescriptors;
  }
  public static JetScope getExpressionMemberScope(
      @NotNull ResolveSession resolveSession, @NotNull JetExpression expression) {
    DelegatingBindingTrace trace =
        new DelegatingBindingTrace(
            resolveSession.getBindingContext(),
            "trace to resolve a member scope of expression",
            expression);

    if (expression instanceof JetReferenceExpression) {
      QualifiedExpressionResolver qualifiedExpressionResolver =
          resolveSession.getInjector().getQualifiedExpressionResolver();

      // In some type declaration
      if (expression.getParent() instanceof JetUserType) {
        JetUserType qualifier = ((JetUserType) expression.getParent()).getQualifier();
        if (qualifier != null) {
          Collection<? extends DeclarationDescriptor> descriptors =
              qualifiedExpressionResolver.lookupDescriptorsForUserType(
                  qualifier, getExpressionResolutionScope(resolveSession, expression), trace);

          for (DeclarationDescriptor descriptor : descriptors) {
            if (descriptor instanceof LazyPackageDescriptor) {
              return ((LazyPackageDescriptor) descriptor).getMemberScope();
            }
          }
        }
      }

      // Inside import
      if (PsiTreeUtil.getParentOfType(expression, JetImportDirective.class, false) != null) {
        NamespaceDescriptor rootPackage = resolveSession.getPackageDescriptorByFqName(FqName.ROOT);
        assert rootPackage != null;

        if (expression.getParent() instanceof JetDotQualifiedExpression) {
          JetExpression element =
              ((JetDotQualifiedExpression) expression.getParent()).getReceiverExpression();
          String name = ((JetFile) expression.getContainingFile()).getPackageName();

          NamespaceDescriptor filePackage =
              name != null
                  ? resolveSession.getPackageDescriptorByFqName(new FqName(name))
                  : rootPackage;
          assert filePackage != null : "File package should be already resolved and be found";

          JetScope scope = filePackage.getMemberScope();
          Collection<? extends DeclarationDescriptor> descriptors;

          if (element instanceof JetDotQualifiedExpression) {
            descriptors =
                qualifiedExpressionResolver.lookupDescriptorsForQualifiedExpression(
                    (JetDotQualifiedExpression) element,
                    rootPackage.getMemberScope(),
                    scope,
                    trace,
                    false,
                    false);
          } else {
            descriptors =
                qualifiedExpressionResolver.lookupDescriptorsForSimpleNameReference(
                    (JetSimpleNameExpression) element,
                    rootPackage.getMemberScope(),
                    scope,
                    trace,
                    false,
                    false,
                    false);
          }

          for (DeclarationDescriptor descriptor : descriptors) {
            if (descriptor instanceof NamespaceDescriptor) {
              return ((NamespaceDescriptor) descriptor).getMemberScope();
            }
          }
        } else {
          return rootPackage.getMemberScope();
        }
      }

      // Inside package declaration
      JetNamespaceHeader namespaceHeader =
          PsiTreeUtil.getParentOfType(expression, JetNamespaceHeader.class, false);
      if (namespaceHeader != null) {
        NamespaceDescriptor packageDescriptor =
            resolveSession.getPackageDescriptorByFqName(
                namespaceHeader.getParentFqName((JetReferenceExpression) expression));
        if (packageDescriptor != null) {
          return packageDescriptor.getMemberScope();
        }
      }
    }

    return null;
  }