### Question:
HBSEOutputFormat extends TextVertexOutputFormat<Text, VertexData, Text> { @Override public TextVertexWriter createVertexWriter(TaskAttemptContext context) throws IOException, InterruptedException { return new SBVertexWriter(); }  @Override TextVertexWriter createVertexWriter(TaskAttemptContext context);  }### Answer:
@Test public void testWriterDefault() throws IOException, InterruptedException { TaskAttemptContext tac = mock(TaskAttemptContext.class); when(tac.getConfiguration()).thenReturn(conf); TextVertexWriter writer = createVertexWriter(tac); writer.setConf(conf); writer.initialize(tac); writer.writeVertex(vertex); verify(tw).write(new Text("1"), new Text("0.0")); writer.writeVertex(vertex2); verify(tw).write(new Text("2"), new Text("1.0")); }