code: def _test_builder_to_backend_stress_with_epsilon(
      compute_unit,
      backend,
      op_name,
      epsilon_val,
      x_eps_dtype,
  ):
      x_dtype, epsilon_dtype = x_eps_dtype
  
      x = np.array([[1, 2, 3], [4, 5, 6]], dtype=x_dtype)
      epsilon = epsilon_dtype(epsilon_val)
  
      def _calculate_by_np():
          if op_name == "inverse":
              return 1 / (x + epsilon)
          elif op_name == "log":
              return np.log(x + epsilon)
          elif op_name == "rsqrt":
              return 1.0 / np.sqrt(x + epsilon)
          else:
              raise ValueError(f"Invalid op {op_name}")
  
      def build(x):
          return getattr(mb, op_name)(x=x, epsilon=epsilon)
  
      x_mb_dtype = types.numpy_type_to_builtin_type(x_dtype)
      run_compare_builder(
          build,
          input_placeholders={
              "x": mb.placeholder(shape=x.shape, dtype=x_mb_dtype)
          },
          input_values={"x": x},
          expected_output_types=x.shape + (x_mb_dtype,),
          expected_outputs=_calculate_by_np(),
          compute_unit=compute_unit,
          backend=backend,
          atol=1e-2 if x_dtype == np.float16 else 1e-4,
          rtol=1e-3 if x_dtype == np.float16 else 1e-5,
      )
  
imports: import itertools
  import numpy
  import pytest
  import scipy
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Function, get_new_symbol, types
  from coremltools.converters.mil.mil.ops.tests.iOS14 import backends
  from coremltools.converters.mil.mil.ops.tests.testing_utils import run_compare_builder
  from coremltools.converters.mil.mil.types.symbolic import is_compatible_symbolic_vector
  from coremltools.converters.mil.testing_reqs import compute_units
  from coremltools.converters.mil.testing_utils import ssa_fn
label_desc: Use image node_id 28 for calling the TestElementwiseUnary obj's underlying member method code with example usage: obj._test_builder_to_backend_stress_with_epsilon(compute_unit, backend, op_name, epsilon_val, x_eps_dtype) and returns: getattr, unknown, np, unknown