@Test
public void testApply() {

  Geometry geometry = mock(Geometry.class);
  Geometry newGeometry = mock(Geometry.class);
  GeometryOperator.Context context = new GeometryOperator.Context();
  when(childGeometryFunction.apply(geometry, context)).thenReturn(newGeometry);
  Geometry result = geometryOperatorList.apply(geometry, context);
  assertThat(result, is(newGeometry));
}