function _transferByPartition(
  bytes32 _fromPartition,
  address _operator,
  address _from,
  address _to,
  uint256 _value,
  bytes memory _data,
  bytes memory _operatorData
) internal returns (bytes32) {
  require(_to != address(0), EC_57_INVALID_RECEIVER);

  // If the `_operator` is attempting to transfer from a different `_from`
  // address, first check that they have the requisite operator or
  // allowance permissions.
  if (_from != _operator) {
    require(
      _isOperatorForPartition(_fromPartition, _operator, _from) ||
        (_value <= _allowedByPartition[_fromPartition][_from][_operator]),
      EC_53_INSUFFICIENT_ALLOWANCE
    );

    // If the sender has an allowance for the partition, that should
    // be decremented
    if (_allowedByPartition[_fromPartition][_from][_operator] >= _value) {
      _allowedByPartition[_fromPartition][_from][
        msg.sender
      ] = _allowedByPartition[_fromPartition][_from][_operator].sub(_value);
    } else {
      _allowedByPartition[_fromPartition][_from][_operator] = 0;
    }
  }

  _callPreTransferHooks(
    _fromPartition,
    _operator,
    _from,
    _to,
    _value,
    _data,
    _operatorData
  );

  require(
    _balanceOfByPartition[_from][_fromPartition] >= _value,
    EC_52_INSUFFICIENT_BALANCE
  );

  bytes32 toPartition = PartitionUtils._getDestinationPartition(
    _data,
    _fromPartition
  );

  _removeTokenFromPartition(_from, _fromPartition, _value);
  _addTokenToPartition(_to, toPartition, _value);
  _callPostTransferHooks(
    toPartition,
    _operator,
    _from,
    _to,
    _value,
    _data,
    _operatorData
  );

  emit Transfer(_from, _to, _value);
  emit TransferByPartition(
    _fromPartition,
    _operator,
    _from,
    _to,
    _value,
    _data,
    _operatorData
  );

  if (toPartition != _fromPartition) {
    emit ChangedPartition(_fromPartition, toPartition, _value);
  }

  return toPartition;
}