code: def _run_interface(self, runtime):
      import nibabel as nb
  
      data1 = np.asanyarray(nb.load(self.inputs.volume1))
      data2 = np.asanyarray(nb.load(self.inputs.volume2))
  
      if not np.array_equal(data1, data2):
          raise RuntimeError("Input images are not exactly equal")
      return runtime
  
imports: import os
  import re
  import numpy
  from ..base import traits, TraitedSpec, DynamicTraitedSpec, File, Undefined, isdefined, OutputMultiPath, InputMultiPath, BaseInterface, BaseInterfaceInputSpec, Str, SimpleInterface
  from ..io import IOBase, add_traits
  from ...utils.filemanip import ensure_list, copyfile, split_filename
label_desc: Use image node_id 1 for calling the AssertEqual obj's underlying member method code with example usage: obj._run_interface(runtime) and returns: runtime