code: def save_raw(self):
          
          length = ctypes.c_ulong()
          cptr = ctypes.POINTER(ctypes.c_char)()
          _check_call(_LIB.XGBoosterGetModelRaw(self.handle,
                                                ctypes.byref(length),
                                                ctypes.byref(cptr)))
          return ctypes2buffer(cptr, length.value)
docs: Save the model to a in memory buffer represetation
  
          Returns
          -------
          a in memory buffer represetation of the model