def match(trace, source, destination, channel=None):
    """
    Find matching rows in the k7
    :param pandas.Dataframe trace:
    :param int source:
    :param int destination:
    :param int channel:
    :return: None | pandas.core.series.Series
    """
    for index, row in trace.iterrows():
        if row['src'] == source and row['dst'] == destination and row['channel'
            ] == channel:
            return row
    return None
