Get all the ChangeSets of this workitem

        :return: a :class:`list` contains all the
            :class:`rtcclient.models.ChangeSet` objects
        :rtype: list

def getChangeSets(self):
        """Get all the ChangeSets of this workitem

        :return: a :class:`list` contains all the
            :class:`rtcclient.models.ChangeSet` objects
        :rtype: list
        """

        changeset_tag = ("rtc_cm:com.ibm.team.filesystem.workitems."
                         "change_set.com.ibm.team.scm.ChangeSet")
        return (self.rtc_obj
                    ._get_paged_resources("ChangeSet",
                                          workitem_id=self.identifier,
                                          customized_attr=changeset_tag,
                                          page_size="10"))