The source code of the Stenway ReliableTXT reference library can be found on GitHub
import sys
import stenway.reliabletxt
from stenway.reliabletxt import *
document = ReliableTxtDocument("abc\U00020007\u6771", ReliableTxtEncoding.UTF_16)
document.setCodePoints([0x61, 0x20007, 0x62])
print(document.getCodePoints())
document.save("Test.txt")