'Append an attribute name/value into L{Content.data}.
@param name: The attribute name
@type name: basestring
@param value: The attribute\'s value
@type value: basestring
@param content: The current content being unmarshalled.
@type content: L{Content}'

def append_attribute(self, name, value, content):

    key = name
    key = ('_%s' % reserved.get(key, key))
    setattr(content.data, key, value)
