code: def _run(self, x, y):
      if (
          x.dtype.kind not in _acceptable_str_dtypes
          or y.dtype.kind not in _acceptable_str_dtypes
      ):
          raise TypeError(
              f"Inputs must be string tensors, received dtype {x.dtype} and {y.dtype}"
          )
      # As per onnx/mapping.py, object numpy dtype corresponds to TensorProto.STRING
      return (
          np.char.add(x.astype(np.str_), y.astype(np.str_)).astype(
              object
          ),
      )
  
imports: import numpy
  from onnx.reference.op_run import OpRun
label_desc: Use image node_id 1 for calling the StringConcat obj's underlying member method code with example usage: obj._run(x, y) and returns: np