code: def _run_interface(self, runtime):
      runtime.returncode = 0
      return runtime
  
imports: import sys
  import os
  import pytest
  from nipype.pipeline import engine
  from nipype.interfaces import base
label_desc: Use image node_id 1 for calling the SingleNodeTestInterface obj's underlying member method code with example usage: obj._run_interface(runtime) and returns: runtime