code: def export_triu_square_neg() -> None:
      node = onnx.helper.make_node(
          "Trilu",
          inputs=["x", "k"],
          outputs=["y"],
      )
  
      x = np.random.randint(10, size=(2, 3, 3)).astype(np.int64)
      k = np.array(-1).astype(np.int64)
      # X:
      # [[[4, 6, 9],
      #   [7, 5, 4],
      #   [8, 1, 2]],
      #
      #  [[1, 4, 9],
      #   [9, 6, 3],
      #   [8, 9, 8]]]
      # expect result:
      # [[[4, 6, 9],
      #   [7, 5, 4],
      #   [0, 1, 2]],
      #
      #  [[1, 4, 9],
      #   [9, 6, 3],
      #   [0, 9, 8]]]
      y = triu_reference_implementation(x, int(k))
      expect(
          node, inputs=[x, k], outputs=[y], name="test_triu_square_neg"
      )
  
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 7 for calling the Trilu obj's underlying member method code with example usage: obj.export_triu_square_neg() without return types