code: def __Finish(self, rootTable, sizePrefix):
          
          N.enforce_number(rootTable, N.UOffsetTFlags)
          prepSize = N.UOffsetTFlags.bytewidth
          if sizePrefix:
              prepSize += N.Int32Flags.bytewidth
          self.Prep(self.minalign, prepSize)
          self.PrependUOffsetTRelative(rootTable)
          if sizePrefix:
              size = len(self.Bytes) - self.Head()
              N.enforce_number(size, N.Int32Flags)
              self.PrependInt32(size)
          self.finished = True
          return self.Head()
docs: Finish finalizes a buffer, pointing to the given `rootTable`.