code: def _run_interface(self, runtime):
      global _sum
      global _sum_operands
      runtime.returncode = 0
      self._results["operands"] = self.inputs.input1
      self._results["output1"] = sum(self.inputs.input1)
      _sum_operands.append(self.inputs.input1)
      _sums.append(sum(self.inputs.input1))
      return runtime
  
imports: import pytest
  from ....None import config
  from ...None import engine
  from ....interfaces import base
  from ....interfaces.utility import IdentityInterface, Function, Merge
  from ....interfaces.base import traits, File
label_desc: Use image node_id 1 for calling the SumInterface obj's underlying member method code with example usage: obj._run_interface(runtime) and returns: runtime