code: def get_symbol(x):
      
      hdl = SymbolHandle()
      check_call(_LIB.MXAutogradGetSymbol(x.handle, ctypes.byref(hdl)))
      return Symbol(hdl)
docs: Retrieve recorded computation history as `Symbol`.
  
      Parameters
      ----------
      x : NDArray
          Array representing the head of computation graph.
  
      Returns
      -------
      Symbol
          The retrieved Symbol.