code: def export_uint4() -> None:
      node = onnx.helper.make_node(
          "QuantizeLinear",
          inputs=["x", "y_scale", "y_zero_point"],
          outputs=["y"],
          axis=0,
      )
  
      x = np.array(
          [
              [0.0, 2.5, 4.8, 8.6],
              [-30, -20, 6, 9],
              [12, 15, 16, 40],
          ]
      ).astype(np.float32)
  
      y_scale = np.asarray([2.0, 3.0, 4.0], dtype=np.float32)
      y_zero_point = make_tensor(
          "zero_point",
          TensorProto.UINT4,
          y_scale.shape,
          np.ones_like(y_scale),
      )
      y = make_tensor(
          "y",
          TensorProto.UINT4,
          x.shape,
          [1, 2, 3, 5, -1, -1, 3, 4, 4, 5, 5, 11],
      )
  
      expect(
          node,
          inputs=[x, y_scale, y_zero_point],
          outputs=[y],
          name="test_quantizelinear_uint4",
      )
  
file_path: onnx/onnx/backend/test/case/node/quantizelinear.py
imports: import numpy
  import onnx
  from onnx import TensorProto
  from onnx.backend.test.case.base import Base
  from onnx.backend.test.case.node import expect
  from onnx.helper import make_tensor
label_desc: Use image node_id 7 for calling the QuantizeLinear obj's underlying member method code with example usage: obj.export_uint4() without return types