'UTF8 encodes all of the NVP values.'

def _encode_utf8(self, **kwargs):

    if is_py3:
        return kwargs
    unencoded_pairs = kwargs
    for i in unencoded_pairs.keys():
        if isinstance(unencoded_pairs[i], types.UnicodeType):
            unencoded_pairs[i] = unencoded_pairs[i].encode('utf-8')
    return unencoded_pairs
