code: def test_builder_rsqrt_eval(self):
      val = np.array([[1, 2, 3], [4, 5, 6]], dtype=np.float32)
      v = mb.rsqrt(x=val)
      expected_outputs = np.array(
          [[1.0, 0.70710678, 0.57735027], [0.5, 0.4472136, 0.40824829]],
          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 19 for calling the TestElementwiseUnary obj's underlying member method code with example usage: obj.test_builder_rsqrt_eval() without return types