def has_output_ports(self):
        return len(self.output_ports)>0
alternate: manage.py can execute user commands if settings are provided in environment
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/inspector.py/PipelineInspector.has_output_ports--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/tests/regressiontests/admin_scripts/tests.py/ManageAlternateSettings.test_custom_command_with_environment