code: def testOptimizeLayoutTiebreak(self):
      x1 = mtf.zeros(self.mesh, "a:10,b:5")
      x2 = mtf.zeros(self.mesh, "b:5,c:20")
      mtf.einsum([x1, x2], "a:10,c:20")
      # Rewrite mesh_shape to have a dummy dimension.
      self.mesh_shape = mtf.convert_to_shape("m1:4,m2:2,m3:1")
      optimizer = self.get_layout_optimizer()
      layout = optimizer.solve()
      self.assertEqual(layout, "a:m2;b:m3;c:m1")
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import mesh_tensorflow
  from mesh_tensorflow.auto_mtf import layout_optimizer
  from mesh_tensorflow.auto_mtf import memory_estimator
  import six
  import tensorflow.compat.v1
label_desc: Use image node_id 6 for calling the OptimizeLayoutTest obj's underlying member method code with example usage: obj.testOptimizeLayoutTiebreak() without return types