'Initialize the MediaInstance
:returns: twilio.rest.api.v2010.account.message.media.MediaInstance
:rtype: twilio.rest.api.v2010.account.message.media.MediaInstance'

def __init__(self, version, payload, account_sid, message_sid, sid=None):

    super(MediaInstance, self).__init__(version)
    self._properties = {'account_sid': payload['account_sid'], 'content_type': payload['content_type'], 'date_created': deserialize.rfc2822_datetime(payload['date_created']), 'date_updated': deserialize.rfc2822_datetime(payload['date_updated']), 'parent_sid': payload['parent_sid'], 'sid': payload['sid'], 'uri': payload['uri']}
    self._context = None
    self._solution = {'account_sid': account_sid, 'message_sid': message_sid, 'sid': (sid or self._properties['sid'])}
