code: public static final long fromVertexId(long id) {
          Preconditions.checkArgument(id > 0, "Invalid vertex id provided: %s", id);
          return IDManager.VertexIDType.NormalVertex.removePadding(id);
      }
docs: Converts a Titan vertex id to the user provided id as the inverse mapping of {@link #toVertexId(long)}.
  
  @param id Titan vertex id (must be positive)
  @return original user provided id