@classmethod
def prefixed_to_namespaced(C, prefixed_name, namespaces):
    """for a given prefix:name, return {namespace}name from the given namespaces dict
        """
    if ':' not in prefixed_name:
        return prefixed_name
    else:
        prefix, name = prefixed_name.split(':')
        namespace = namespaces[prefix]
        return '{%s}%s' % (namespace, name)
