code: def export() -> None:
      node = onnx.helper.make_node(
          "IsNaN",
          inputs=["x"],
          outputs=["y"],
      )
  
      x = np.array(
          [-1.2, np.nan, np.inf, 2.8, np.NINF, np.inf], dtype=np.float32
      )
      y = np.isnan(x)
      expect(node, inputs=[x], outputs=[y], name="test_isnan")
  
file_path: onnx/onnx/backend/test/case/node/isnan.py
imports: 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 IsNaN obj's underlying member method code with example usage: obj.export() without return types