@Nullable
  public Collection<VirtualFile> detectProjectMappings(@NotNull Project project,
                                                       @NotNull Collection<VirtualFile> projectRoots,
                                                       @NotNull Set<VirtualFile> mappedDirs) {
    return null;
  }
@Nullable
  public Collection<VirtualFile> detectProjectMappings(@NotNull Project project,
                                                       @NotNull Collection<VirtualFile> projectRoots,
                                                       @NotNull Set<VirtualFile> mappedDirs)