def choose_boundary():
    """
    Our embarrassingly-simple replacement for mimetools.choose_boundary.
    """
    boundary = binascii.hexlify(os.urandom(16))
    if not six.PY2:
        boundary = boundary.decode("ascii")
    return boundary

    Our embarrassingly-simple replacement for mimetools.choose_boundary.
    
product/gradle-plugin/src/main/python/pip/_vendor/urllib3/filepost.py