code: def _dtype(*data, dtype=None, dtype_first=False):  # type: ignore
      numpy_type = _CommonRandom.numpy_type(dtype)
      if dtype_first and numpy_type is not None:
          if dtype != 0:  # type: ignore
              return numpy_type
          if data:
              return data[0].dtype
          raise RuntimeError(
              f"dtype cannot be None for a random operator {_CommonRandom.__name__!r}, "
              f"numpy_type={numpy_type}, len(data)={len(data)}."
          )
      res = None
      if not data:
          res = numpy_type
      elif numpy_type is not None:
          res = numpy_type
      elif hasattr(data[0], "dtype"):
          res = data[0].dtype
      if res is None:
          raise RuntimeError(
              f"dtype cannot be None, numpy_type={numpy_type}, type(data[0])={type(data[0])}."
          )
      return res
  
file_path: onnx/onnx/reference/ops/_op_common_random.py
imports: import numpy
  from onnx.helper import tensor_dtype_to_np_dtype
  from onnx.reference.op_run import OpRun
label_desc: Use image node_id 3 for calling the _CommonRandom obj's underlying member method code with example usage: obj._dtype() and returns: res, numpy_type, data