code: def init_element_masked(initial_mean, initial_cov):
      """Represents the message from a masked value at the initial timestep."""
      with tf.name_scope("init_element_masked"):
          return FilterElements(
              posterior_link_matrix=tf.zeros_like(initial_cov),
              posterior_mean=initial_mean,
              posterior_cov=initial_cov,
              marginal_likelihood_meanprec=tf.zeros_like(initial_mean),
              marginal_likelihood_prec=tf.zeros_like(initial_cov),
          )
  
imports: import collections
  import functools
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import mvn_tril
  from tensorflow_probability.python.internal import dtype_util
  from tensorflow_probability.python.internal import prefer_static
  from tensorflow_probability.python.internal import samplers
  from tensorflow_probability.python.math import linalg
  from tensorflow_probability.python.math.scan_associative import scan_associative
label_desc: Use image node_id 6 for calling a global function with example usage: init_element_masked(initial_mean, initial_cov) and returns: FilterElements