def METHOD_NAME(self):
    expected_result = self._vector + self._vector
    src = blocks.file_source(gr.sizeof_float, self._datafilename, True)
    src.set_begin_tag(pmt.string_to_symbol("file_begin"))
    head = blocks.head(gr.sizeof_float, 2 * len(self._vector))
    snk = blocks.vector_sink_f()
    self.tb.connect(src, head, snk)
    self.tb.run()
    result_data = snk.data()
    self.assertFloatTuplesAlmostEqual(expected_result, result_data)
    tags = snk.tags()
    self.assertEqual(len(tags), 2)
    self.assertEqual(str(tags[0].key), "file_begin")
    self.assertEqual(str(tags[0].value), "0")
    self.assertEqual(tags[0].offset, 0)
    self.assertEqual(str(tags[1].key), "file_begin")
    self.assertEqual(str(tags[1].value), "1")
    self.assertEqual(tags[1].offset, 1000)