'Set metadata for an object
:param obj: The blob object
:type obj: :class:`Object`
:param meta_data: Metadata key value pairs
:type meta_data: ``dict``'

def ex_set_object_metadata(self, obj, meta_data):

    object_path = self._get_object_path(obj.container, obj.name)
    params = {'comp': 'metadata'}
    headers = {}
    self._update_metadata(headers, meta_data)
    response = self.connection.request(object_path, method='PUT', params=params, headers=headers)
    if (response.status != httplib.OK):
        response.parse_error('Setting    metadata')
