def message(msg_content, title=None, content_type=None, extras=None):
    """Inner-conn push message payload creation.

    :param msg_content: Required, string
    :param title: Optional, string
    :keyword content_type: Optional, MIME type of the body
    :keyword extras: Optional, dictionary of string values.

    """
    payload = {
        'msg_content': msg_content,
    }
    if title is not None:
        payload['title'] = title
    if content_type is not None:
        payload['content_type'] = content_type
    if extras is not None:
        payload['extras'] = extras
    return payload