public static <K extends WritableComparable, V extends Writable>
  Writable getEntry(MapFile.Reader[] readers,
                                  Partitioner<K, V> partitioner,
                                  K key,
                                  V value) throws IOException {
    int readerLength = readers.length;
    int part;
    if (readerLength <= 1) {
      part = 0;
    } else {
      part = partitioner.getPartition(key, value, readers.length);
    }
    return readers[part].get(key, value);
  }
@SuppressWarnings("static-access")
  @Test
  public void testPartitionerShouldNotBeCalledWhenOneReducerIsPresent()
      throws Exception {
    MapFileOutputFormat outputFormat = new MapFileOutputFormat();
    Reader reader = Mockito.mock(Reader.class);
    Reader[] readers = new Reader[]{reader};
    outputFormat.getEntry(readers, new MyPartitioner(), new Text(), new Text());
    assertTrue(!MyPartitioner.isGetPartitionCalled());
  }