code: def _initialize_mesh_dimension_name_to_size(self, mesh_shape):
      
      mesh_dimension_name_to_size = {}  # {string: int}
      for mesh_dimension in mesh_shape.dims:
        mesh_dimension_name_to_size[mesh_dimension.name] = mesh_dimension.size
      return mesh_dimension_name_to_size
docs: Initializer for self._mesh_dimension_name_to_size.
  
      Args:
        mesh_shape: an mtf.Shape.
  
      Returns:
        A {string: int} mapping mesh dimension names to their sizes.