def register_element_cls(tag, cls):
    nspfx, tagroot = tag.split(':')
    namespace = element_class_lookup.get_namespace(nsmap[nspfx])
    namespace[tagroot] = cls
RFC 2822's hard limit is 998 characters per line.
dataset/ETHPy150Open python-openxml/python-docx/docx/oxml/__init__.py/register_element_cls--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/tests/regressiontests/logging_tests/tests.py/AdminEmailHandlerTest.test_truncate_subject