def get_channel_uploads_id(handle, channel_id):
    """ Returns 'upload playlist ID' for given channel_id

    Parameters:
        handle(object):  Youtube handle for authorizing requests to the
            Youtube API. See function `get_handle` for further details.
        channel_id(str): Unique channel identifier. To convert channel
            names to the identifier, see:
            http://johnnythetank.github.io/youtube-channel-name-converter/
    """

    json_result = handle.channels().list(
        part='snippet,contentDetails', id=channel_id).execute()

    return json_result['items'][0]['contentDetails']['relatedPlaylists'][
        'uploads']