delete_collection specify custom partition

I want to delete virtual servers that some other partitions ,but delete_collection() only delete virtual servers in a partition that named Common.
eg:
mgmt = ManagementRoot("121.42.101.152", "admin", "admin")
requests_params = {'params': 'options=* '}
mgmt.tm.ltm.virtuals.delete_collection(requests_params=requests_params)


Am I miss anything?