PlaceUOffsetT prepends a UOffsetT to the Builder, without checking
        for space.

def PlaceUOffsetT(self, x):
        """PlaceUOffsetT prepends a UOffsetT to the Builder, without checking
        for space.
        """
        N.enforce_number(x, N.UOffsetTFlags)
        self.head = self.head - N.UOffsetTFlags.bytewidth
        encode.Write(packer.uoffset, self.Bytes, self.Head(), x)