@Test
public void testAttributeToLineStringWithNullGeometry() {

  Attribute attribute =
      new AttributeImpl(FIELD, Arrays.asList("POINT ( 0 0 )", "POINT ( 10 10 )"));
  GeometryOperator geometryOperator = mock(GeometryOperator.class);
  when(geometryOperator.apply(any(), any())).thenReturn(null);
  String lineString =
      GeometryUtility.attributeToLineString(
          attribute, geometryOperator, new GeometryOperator.Context());
  verify(geometryOperator).apply(any(), any());
  assertThat(lineString, is(nullValue()));
}