code: def test_empty(self, xp):
      return xp.append(xp.array([]), xp.arange(10))
  
imports: import unittest
  import pytest
  import numpy
  import cupy
  from cupy import testing
label_desc: Use image node_id 9 for calling the TestAppend obj's underlying member method code with example usage: obj.test_empty(xp) and returns: xp