code: def _mock_pileup_array_with_reads():
      shape = (10, 15)  # (height, width)
      pileup = np.zeros(shape)
      # Top 5 rows and all other non-read space is left as 0.
      # Like an actual pileup with 4 reads, each 8 bases long.
      pileup[5, 0:8] = 254
      pileup[6, 1:9] = 254
      pileup[7, 4:12] = 100  # One read with low value.
      pileup[8, 6:14] = 254
      pileup[8, 8:10] = 100  # Two bases of another read with low value.
      return pileup
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import glob
  import os
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.testing import test_utils
  from third_party.nucleus.util import vis
  from tensorflow.core.example import example_pb2
  from tensorflow.core.example import feature_pb2
label_desc: Use image node_id 6 for calling a global function with example usage: _mock_pileup_array_with_reads() and returns: pileup