'This method is responsible for establishing connection
with storage nodes and sending the data to each one of those
nodes. The process of transferring data is specific to each
Storage Policy, thus it is required for each policy specific
ObjectController to provide their own implementation of this method.
:param req: the PUT Request
:param data_source: an iterator of the source of the data
:param nodes: an iterator of the target storage nodes
:param partition: ring partition number
:param outgoing_headers: system headers to storage nodes
:return: Response object'

def _store_object(self, req, data_source, nodes, partition, outgoing_headers):

    raise NotImplementedError()
