wf:[colon-separated list of features]

bVALUE Set the frame payload. If a masking key is present, the value is encoded automatically.
cINTEGER Set the op code. This can either be an integer from 0-15, or be one of the following opcode names: text (the default), continue, binary, close, ping, pong.
dOFFSET Disconnect after OFFSET bytes.
[-]fin Set or un-set the fin bit.
iOFFSET,VALUE Inject the specified value at the offset.
[-]mask Set or un-set the mask bit.
pOFFSET,SECONDS Pause for SECONDS seconds after OFFSET bytes. SECONDS can be an integer or "f" to pause forever.
r Create a "raw" frame - disables auto-generation of the masking key if the mask bit is on.
[-]rsv1 Set or un-set the rsv1 bit.
[-]rsv2 Set or un-set the rsv2 bit.
[-]rsv3 Set or un-set the rsv3 bit.