Return unique values in a list in the original order. See:  \
        http://www.peterbe.com/plog/uniqifiers-benchmark

    Args:
      seq (list): original list.

    Returns:
      list: list without duplicates preserving original order.

def uniquify(seq):
    """Return unique values in a list in the original order. See:  \
        http://www.peterbe.com/plog/uniqifiers-benchmark

    Args:
      seq (list): original list.

    Returns:
      list: list without duplicates preserving original order.

    """

    seen = set()
    seen_add = seen.add
    return [x for x in seq if x not in seen and not seen_add(x)]