code: def test_builder_cos_eval(self):
      val = np.array([[-1, 2, -3], [4, -5, 6]], dtype=np.float32)
      v = mb.cos(x=val)
      expected_outputs = np.array(
          [
              [0.54030231, -0.41614684, -0.9899925],
              [-0.65364362, 0.28366219, 0.96017029],
          ],
          dtype=np.float32,
      )
  
      assert is_close(expected_outputs, v.val)
  
imports: import scipy
  from coremltools.converters.mil import testing_reqs
  from coremltools.converters.mil.testing_reqs import *
  from .testing_utils import run_compare_builder
label_desc: Use image node_id 10 for calling the TestElementwiseUnary obj's underlying member method code with example usage: obj.test_builder_cos_eval() without return types