code: def test_fill_diagonal(self, xp, dtype):
      a = testing.shaped_arange(self.shape, xp, dtype)
      val = self._compute_val(xp)
      xp.fill_diagonal(a, val=val, wrap=self.wrap)
      return a
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 2 for calling the TestFillDiagonal obj's underlying member method code with example usage: obj.test_fill_diagonal(xp, dtype) and returns: a