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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def delete(key,
           host=DEFAULT_HOST,
           port=DEFAULT_PORT,
           time=DEFAULT_TIME):
    '''
    Delete a key from memcache server

    CLI Example:

    .. code-block:: bash

        salt '*' memcached.delete <key>
    '''
    if not isinstance(time, six.integer_types):
        raise SaltInvocationError('\'time\' must be an integer')
    conn = _connect(host, port)
    _check_stats(conn)
    return bool(conn.delete(key, time))