public boolean contains(@NotNull VirtualFile file) {
    if (myFilesSet == null) {
      if (myType == CUSTOM) {
        // optimization
        if (myScope != null) return myScope.contains(file);
      }
      if (myType == PROJECT) {  //optimization
        ProjectFileIndex index = ProjectRootManager.getInstance(myProject).getFileIndex();
        return index.isInContent(file) && !isFilteredOut(file);
      }
    }

    return getFileSet().contains(file);
  }
public boolean contains(@NotNull VirtualFile file)