code: def mu() -> Parameter:
      return Parameter(rng.randn(Nn, Ln))
  
imports: from unittest.mock import patch
  import numpy
  import pytest
  import tensorflow
  from check_shapes import ShapeChecker, check_shapes
  from numpy.testing import assert_allclose, assert_almost_equal
  import gpflow
  from gpflow import Parameter, default_float, default_jitter
  from gpflow.base import AnyNDArray, TensorType
  from gpflow.inducing_variables import InducingPoints
  from gpflow.kernels import Kernel
  from gpflow.kullback_leiblers import gauss_kl, prior_kl
  from gpflow.utilities.bijectors import triangular
label_desc: Use image node_id 3 for calling a global function with example usage: mu() and returns: Parameter