'Return the channel object if given its key.
Also searches its aliases.
Args:
channelkey (str): Channel key to search for.
Returns:
channel (Channel or None): A channel match.'

@returns_typeclass
def get_channel(self, channelkey):

    channels = self.filter(db_key__iexact=channelkey)
    if (not channels):
        channels = [channel for channel in self.all() if (channelkey in channel.aliases.all())]
    if channels:
        return channels[0]
    return None
