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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 _add_variable_proxy_methods(var, proxy_tensor):
 """Proxy methods of underlying variable. This enables our custom getters to still work with, e.g., batch norm. Args: var: Variable to proxy proxy_tensor: Tensor that is identity of var """

  proxy_tensor.read_value = lambda: tf.identity(proxy_tensor)
  proxy_tensor.assign_sub = var.assign_sub
  proxy_tensor.assign = var.assign
  proxy_tensor.initialized_value = var.initialized_value