public static boolean isStdLib(@NotNull VirtualFile vFile, @Nullable Sdk pythonSdk) {
    if (pythonSdk != null) {
      @Nullable VirtualFile originFile = vFile;
      @NotNull String originPath = vFile.getPath();
      boolean checkOnRemoteFS = false;
      // All binary skeletons are collected under the same root regardless of their original location.
      // Because of that we need to use paths to the corresponding binary modules recorded in their headers.
      final PySkeletonHeader header = readSkeletonHeader(originFile, pythonSdk);
      if (header != null) {
        // Binary module paths in skeleton headers of Mock SDK don't map to actual physical files.
        // Fallback to the old heuristic for these stubs.
        if (ApplicationManager.getApplication().isUnitTestMode() &&
            Objects.equals(vFile.getParent(), findSkeletonsDir(pythonSdk))) {
          return true;
        }

        final String binaryPath = header.getBinaryFile();
        // XXX Assume that all pre-generated stubs belong to the interpreter's stdlib -- might change in future with PY-32229
        if (binaryPath.equals(PySkeletonHeader.BUILTIN_NAME) || binaryPath.equals(PySkeletonHeader.PREGENERATED)) {
          return true;
        }
        if (isRemote(pythonSdk)) {
          checkOnRemoteFS = true;
          // Actual file is on remote file system and not available
          originFile = null;
        }
        else {
          originFile = VfsUtil.findFileByIoFile(new File(binaryPath), true);
        }
        originPath = binaryPath;
      }
      if (originFile != null) {
        originFile = ObjectUtils.notNull(originFile.getCanonicalFile(), originFile);
        originPath = originFile.getPath();
      }

      final VirtualFile libDir = PySearchUtilBase.findLibDir(pythonSdk);
      if (libDir != null && isUnderLibDirButNotSitePackages(originFile, originPath, libDir, pythonSdk, checkOnRemoteFS)) {
        return true;
      }
      final VirtualFile venvLibDir = PySearchUtilBase.findVirtualEnvLibDir(pythonSdk);
      if (venvLibDir != null && isUnderLibDirButNotSitePackages(originFile, originPath, venvLibDir, pythonSdk, checkOnRemoteFS)) {
        return true;
      }
      if (PyUserSkeletonsUtil.isStandardLibrarySkeleton(vFile)) {
        return true;
      }
      if (PyTypeShed.INSTANCE.isInStandardLibrary(vFile) && PyTypeShed.INSTANCE.isInside(vFile)) {
        return true;
      }
    }
    return false;
  }
public static boolean isStdLib(@NotNull VirtualFile vFile, @Nullable Sdk pythonSdk)