code: def export_gelu_tanh() -> None:
      node = onnx.helper.make_node(
          "Gelu", inputs=["x"], outputs=["y"], approximate="tanh"
      )
  
      x = np.array([-1, 0, 1]).astype(np.float32)
      # expected output [-0.158808, 0., 0.841192]
      y = (
          0.5
          * x
          * (
              1
              + np.tanh(
                  np.sqrt(2 / np.pi) * (x + 0.044715 * np.power(x, 3))
              )
          )
      ).astype(np.float32)
      expect(node, inputs=[x], outputs=[y], name="test_gelu_tanh_1")
  
      x = np.random.randn(3, 4, 5).astype(np.float32)
      # expected output [2.9963627, 3.99993, 4.9999995]
      y = (
          0.5
          * x
          * (
              1
              + np.tanh(
                  np.sqrt(2 / np.pi) * (x + 0.044715 * np.power(x, 3))
              )
          )
      ).astype(np.float32)
      expect(node, inputs=[x], outputs=[y], name="test_gelu_tanh_2")
  
file_path: onnx/onnx/backend/test/case/node/gelu.py
imports: import math
  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 1 for calling the Gelu obj's underlying member method code with example usage: obj.export_gelu_tanh() without return types