@NotNull
  public static MutableDiffRequestChain createMutableChainFromFiles(@Nullable Project project,
                                                                    @NotNull VirtualFile file1,
                                                                    @NotNull VirtualFile file2) {
    return createMutableChainFromFiles(project, file1, file2, null);
  }
@NotNull
  public static MutableDiffRequestChain createMutableChainFromFiles(@Nullable Project project,
                                                                    @NotNull VirtualFile file1,
                                                                    @NotNull VirtualFile file2)