code: def test_gerc(self):
      ref = self.alpha * cupy.outer(self.x, self.y.conj()) + self.a
      if self.mode is not None:
          self.alpha = self.mode.array(self.alpha)
      cublas.gerc(self.alpha, self.x, self.y, self.a)
      cupy.testing.assert_allclose(
          self.a, 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 4 for calling the TestGer obj's underlying member method code with example usage: obj.test_gerc() without return types