android/guava/src/com/google/common/graph/ImmutableGraph.java
@Deprecated
  public static <N> ImmutableGraph<N> copyOf(ImmutableGraph<N> graph) {
    return checkNotNull(graph);
  }
@Deprecated
  public static <N> ImmutableGraph<N> copyOf(ImmutableGraph<N> graph) {
    return checkNotNull(graph);
  }
Simply returns its argument.

@deprecated no need to use this