code: def h(self, x: np.ndarray) -> np.ndarray:
      return np.tanh(x)
  
file_path: onnx/onnx/backend/test/case/node/lstm.py
imports: from typing import Any, Tuple
  import numpy
  import onnx
  from onnx.backend.test.case.base import Base
  from onnx.backend.test.case.node import expect
label_desc: Use image node_id 4 for calling the LSTMHelper obj's underlying member method code with example usage: obj.h(x) and returns: np