@Test
void emptyKeysShouldGiveEmptyList()
{

    //GIVEN
    List<String> keys = Collections.emptyList();
    InternalRecord record =  new InternalRecord( keys, new Value[]{} );
    //WHEN
    List<String> appendedKeys = record.keys();
    //THEN
    assertThat( appendedKeys, equalTo( keys ) );
}