def to_hash
            index_hash = {}
            index_hash['json_claz'] = self.class.name
            index_hash['id'] = id

            index_hash['sensor_type'] = sensor_type
            index_hash['payload'] = payload
            index_hash['created_at'] = created_at
            index_hash
        end
def to_hash
            index_hash = {}
            index_hash['json_claz'] = self.class.name
            index_hash['id'] = id

            index_hash['sensor_type'] = sensor_type
            index_hash['payload'] = payload
            index_hash['created_at'] = created_at
            index_hash
        end
Transform the ruby obj ->  to a Hash