def copyfileobj(fsrc, fdst, length=16*1024):
    """copy data from file-like object fsrc to file-like object fdst"""
    while 1:
        buf = fsrc.read(length)
        if not buf:
            break
        fdst.write(buf)
copy data from file-like object fsrc to file-like object fdst
product/gradle-plugin/src/main/python/pip/_vendor/distlib/_backport/shutil.py