code: def test_subtract(self, device, dtype, batch_size):
      d1 = self._make_rand_data(device, dtype, batch_size)
      d2 = self._make_rand_data(device, dtype, batch_size)
      q1 = Quaternion(d1)
      q2 = Quaternion(d2)
      q3 = q1 - q2
      assert isinstance(q3, Quaternion)
      self.assert_close(q3, d1 - d2)
      q1 -= q2
      self.assert_close(q1, q3)
  
imports: import pytest
  import torch
  from kornia.geometry.quaternion import Quaternion
  from kornia.testing import assert_close
label_desc: Use image node_id 9 for calling the TestQuaternion obj's underlying member method code with example usage: obj.test_subtract(device, dtype, batch_size) without return types