assertThat(throwable).hasMessageThat().startsWith(NODE_STRING);
    assertThat(throwable).hasMessageThat().contains(ERROR_ELEMENT_NOT_IN_GRAPH);
  }
  
  static void assertEdgeNotInGraphErrorMessage(Throwable throwable) {
    assertThat(throwable).hasMessageThat().startsWith(EDGE_STRING);
    assertThat(throwable).hasMessageThat().contains(ERROR_ELEMENT_NOT_IN_GRAPH);
  }