code: def test_dgmm_out(self, dtype):
      self._setup(dtype)
      if self.side == "L":
          ref = cupy.diag(self.x) @ self.a
      elif self.side == "R":
          ref = self.a @ cupy.diag(self.x)
      c = cupy.empty(self.shape, order=self.orderc, dtype=dtype)
      cublas.dgmm(self.side, self.a, self.x, out=c)
      cupy.testing.assert_allclose(c, ref, rtol=self.tol, atol=self.tol)
  
imports: import numpy
  import pytest
  import cupy
  from cupy import cublas
  from cupy import testing
label_desc: Use image node_id 3 for calling the TestDgmm obj's underlying member method code with example usage: obj.test_dgmm_out(dtype) without return types