public XAConnectionFactory xaConnectionFactory(XAConnectionFactory xaConnectionFactory) {
    return TracingXAConnectionFactory.create(xaConnectionFactory, this);
  }
@Test void xaConnectionFactory_doesntDoubleWrap() {
    XAConnectionFactory wrapped = jmsTracing.xaConnectionFactory(mock(XAConnectionFactory.class));
    assertThat(jmsTracing.xaConnectionFactory(wrapped))
      .isSameAs(wrapped);
  }