static ColumnExtractor create(final Column column) {
    final int index = column.index();
    Preconditions.checkArgument(index >= 0, "negative index: " + index);

    return column.namespace() == Namespace.KEY
        ? new KeyColumnExtractor(index)
        : new ValueColumnExtractor(index);
  }
@Test
  public void shouldExtractValueColumn() {
    // Given:
    when(column.namespace()).thenReturn(Namespace.VALUE);
    when(column.index()).thenReturn(1);

    when(value.get(1)).thenReturn("some other value");

    final ColumnExtractor extractor = TimestampColumnExtractors.create(column);

    // When:
    final Object result = extractor.extract(key, value);

    // Then:
    assertThat(result, is("some other value"));
  }