def METHOD_NAME(self):
    block_size = 2
    src_data = (complex(0, 0), complex(1000, -
                                       1000), complex(2000, -
                                                      2000), complex(3000, -
                                                                     3000), complex(4000, -
                                                                                    4000), complex(5000, -
                                                                                                   5000))
    expected_result = (complex(0, 0), complex(125, -
                                              125), complex(250, -
                                                            250), complex(484.375, -
                                                                          484.375), complex(718.75, -
                                                                                            718.75), complex(1048.828125, -
                                                                                                             1048.828125))
    src = blocks.vector_source_c(src_data)
    s2p = blocks.stream_to_vector(gr.sizeof_gr_complex, block_size)
    op = filter.single_pole_iir_filter_cc(0.125, block_size)
    p2s = blocks.vector_to_stream(gr.sizeof_gr_complex, block_size)
    dst = blocks.vector_sink_c()
    self.tb.connect(src, s2p, op, p2s, dst)
    self.tb.run()
    result_data = dst.data()
    self.assertComplexTuplesAlmostEqual(expected_result, result_data, 3)