a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS065 [Section] 5.10 [Statement text] 
The Consumer SHOULD choose to respect this request to change the window state, but since the Portlet cannot depend on that choice it MUST NOT encode this new window state into any of its stateful settings. Rather, the Portlet MUST compute any such impact on stateful settings after the Consumer has actually changed the window state.
WSRP v2.0 Specification
Statement text