@Test public void testIt() { A10ClientImpl c = Mockito.mock(A10ClientImpl.class); RequestBuilder b = new RequestBuilder(c, "test"); Assertions.assertThat(b.getParams()).containsEntry("method", "test").hasSize(1); Assertions.assertThat(b.method("foo").getParams()).containsEntry("method", "foo").hasSize(1); Assertions.assertThat(b.param("a", "1").getParams()) .containsEntry("method", "foo") .containsEntry("a", "1") .hasSize(2); Assertions.assertThat(b.param("a", "2").getParams()) .containsEntry("method", "foo") .containsEntry("a", "2") .hasSize(2); }