question: unregisters a previously registered observer . concode_field_sep String TAG concode_elem_sep PurchaseObserver sPurchaseObserver concode_field_sep void checkBillingSupportedResponse concode_elem_sep void responseCodeReceived concode_elem_sep void responseCodeReceived concode_elem_sep void buyPageIntentResponse concode_elem_sep void purchaseResponse concode_elem_sep void register
target: void function ( PurchaseObserver arg0 ) { Log . d ( TAG , "srini_string" ) ; sPurchaseObserver = null ; }