code: def get_data(self):
          
          if not bool(self._my_map['data']):
              raise errors.IllegalState('no data')
          dbase = JSONClientValidated('repository',
                                      runtime=self._runtime).raw()
          filesys = gridfs.GridFS(dbase)
          return DataInputStream(filesys.get(self._my_map['data']))
docs: Gets the asset content data.
  
          return: (osid.transport.DataInputStream) - the length of the
                  content data
          raise:  OperationFailed - unable to complete request
          *compliance: mandatory -- This method must be implemented.*