code: def _LogMatrix(self, mat, dim):
      logging.info("---- printing the first 10*10 submatrix ----")
      for i in range(min(10, dim)):
          row = ""
          for j in range(min(10, dim)):
              row += " " + str(mat[i][j])
          logging.info(row)
  
imports: import random
  import numpy
  from google.protobuf import text_format
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 4 for calling the VirtualGpuTestUtil obj's underlying member method code with example usage: obj._LogMatrix(mat, dim) without return types