Is there anyway to use iControl REST to enable a ASM policy to a VS in V11.6.1?

bigip.patch("https://10.10.0.21/mgmt/tm/asm/policies/YPwl3HjGvb43lwZ_X6l9bA/{'virtualServers':['/Common/vip-asm']}") {"code":400,"message":"request.body","referer":"10.10.0.1","restOperationId":18899,"errorStack":["java.lang.IllegalArgumentException: request.body","at $000(RestServer.java:43)","at $1.run(RestServer.java:165)","at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)","at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)","at java.lang.Thread.run(Thread.java:744)\n"]}

i try to create a ltm policy assign with a asm policy, and applied the ltm policy to a vip, it's worked.