def METHOD_NAME(self):
    """Test _extract_pipelineparams."""
    p1 = PipelineParam(
        name='param1',
        op_name='op1',
        param_type={'customized_type_a': {
            'property_a': 'value_a'
        }})
    p2 = PipelineParam(name='param2', param_type='customized_type_b')
    p3 = PipelineParam(
        name='param3',
        value='value3',
        param_type={'customized_type_c': {
            'property_c': 'value_c'
        }})
    stuff_chars = ' between '
    payload = str(p1) + stuff_chars + str(p2) + stuff_chars + str(p3)
    params = _extract_pipelineparams(payload)
    self.assertListEqual([p1, p2, p3], params)
    # Expecting the _extract_pipelineparam to dedup the pipelineparams among all the payloads.
    payload = [
        str(p1) + stuff_chars + str(p2),
        str(p2) + stuff_chars + str(p3)
    ]
    params = _extract_pipelineparams(payload)
    self.assertListEqual([p1, p2, p3], params)