@Override
    public void start(final String host, final int port, final String contextPath) {
        startSelectMasterTask(host, String.valueOf(port), contextPath);
    }
start master select task.

@param host host
@param port port
@param contextPath contextPath
shenyu-admin/src/main/java/org/apache/shenyu/admin/mode/cluster/service/ShenyuClusterService.java