@Override
    public String toString() {
        return this.id + "_" + CodecUtil.b64(this.data);
    }
Parse.

@param key the key
@return the client flow execution key
@throws BadlyFormattedFlowExecutionKeyException the badly formatted flow execution key exception
core/cas-server-core-webflow-api/src/main/java/org/apereo/cas/web/flow/executor/ClientFlowExecutionKey.java