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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _initialize_mesh_dimension_name_to_size(self, mesh_shape):
 """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. """

    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