def METHOD_NAME(self, handler_cisco):
    # get hold of the read-only Snmp-object
    snmp_read_only_handler = handler_cisco._get_read_only_handle()
    # replace get-method on Snmp-object with a mock-method
    # for getting all IfAlias
    walkdata = [('.1', b'jomar'), ('.2', b'knut'), ('.3', b'hjallis')]
    expected = {1: 'jomar', 2: 'knut', 3: 'hjallis'}
    snmp_read_only_handler.bulkwalk = Mock(return_value=walkdata)
    assert handler_cisco._get_all_ifaliases() == expected, "getAllIfAlias failed."