code: def compare_backend(backend, test, decimal=5, options=None, verbose=False, context=None):
      
      if backend == "onnxruntime":
          if sys.version_info[0] == 2:
              # onnxruntime is not available on Python 2.
              return            
          from .utils_backend_onnxruntime import compare_runtime
          return compare_runtime(test, decimal, options, verbose)
      else:
          raise ValueError("Does not support backend '{0}'.".format(backend))
docs: The function compares the expected output (computed with
      the model before being converted to ONNX) and the ONNX output
      produced with module *onnxruntime*.
      
      :param backend: backend to use to run the comparison,
          only *onnxruntime* is currently supported
      :param test: dictionary with the following keys:
          - *onnx*: onnx model (filename or object)
          - *expected*: expected output (filename pkl or object)
          - *data*: input data (filename pkl or object)
      :param decimal: precision of the comparison
      :param options: comparison options
      :param context: specifies custom operators
      :param verbose: in case of error, the function may print
          more information on the standard output
      
      The function does not return anything but raises an error
      if the comparison failed.