Get the parent workitem of this workitem

        If no parent, None will be returned.

        :param returned_properties: the returned properties that you want.
            Refer to :class:`rtcclient.client.RTCClient` for more explanations
        :return: a :class:`rtcclient.workitem.Workitem` object
        :rtype: rtcclient.workitem.Workitem

def getParent(self, returned_properties=None):
        """Get the parent workitem of this workitem

        If no parent, None will be returned.

        :param returned_properties: the returned properties that you want.
            Refer to :class:`rtcclient.client.RTCClient` for more explanations
        :return: a :class:`rtcclient.workitem.Workitem` object
        :rtype: rtcclient.workitem.Workitem
        """

        parent_tag = ("rtc_cm:com.ibm.team.workitem.linktype."
                      "parentworkitem.parent")
        rp = returned_properties
        parent = (self.rtc_obj
                      ._get_paged_resources("Parent",
                                            workitem_id=self.identifier,
                                            customized_attr=parent_tag,
                                            page_size="5",
                                            returned_properties=rp))

        # No more than one parent
        if parent:
            # only one element
            return parent[0]
        return None