public static Builder builder() {
    return new Builder();
  }
@Test
  public void testBuilderDoesNotBuildInvalidRequests() {
    assertThatThrownBy(() -> CreateNamespaceResponse.builder().withNamespace(null).build())
        .isInstanceOf(NullPointerException.class)
        .hasMessage("Invalid namespace: null");

    assertThatThrownBy(() -> CreateNamespaceResponse.builder().setProperties(null).build())
        .isInstanceOf(NullPointerException.class)
        .hasMessage("Invalid collection of properties: null");

    Map<String, String> mapWithNullKey = Maps.newHashMap();
    mapWithNullKey.put(null, "hello");
    assertThatThrownBy(
            () -> CreateNamespaceResponse.builder().setProperties(mapWithNullKey).build())
        .isInstanceOf(IllegalArgumentException.class)
        .hasMessage("Invalid property to set: null");

    Map<String, String> mapWithMultipleNullValues = Maps.newHashMap();
    mapWithMultipleNullValues.put("a", null);
    mapWithMultipleNullValues.put("b", "b");
    assertThatThrownBy(
            () ->
                CreateNamespaceResponse.builder().setProperties(mapWithMultipleNullValues).build())
        .isInstanceOf(IllegalArgumentException.class)
        .hasMessage("Invalid value to set for properties [a]: null");
  }