code: def export() -> None:
      values = np.random.randn(5, 5).astype(np.float32)
      node = onnx.helper.make_node(
          "Constant",
          inputs=[],
          outputs=["values"],
          value=onnx.helper.make_tensor(
              name="const_tensor",
              data_type=onnx.TensorProto.FLOAT,
              dims=values.shape,
              vals=values.flatten().astype(float),
          ),
      )
  
      expect(node, inputs=[], outputs=[values], name="test_constant")
  
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 Constant obj's underlying member method code with example usage: obj.export() without return types