def __setitem__(self, key, value):
        key = normalize(key)
        if key in self._v:
            self._v[key] = remove_newlines(value)
            self.changed = True
        else:
            self.prepend(key, remove_newlines(value))
dataset/ETHPy150Open mailgun/flanker/flanker/mime/message/headers/headers.py/MimeHeaders.__setitem__/original