nsISupports** aState,
nsIPresState** aState,
nsLayoutHistoryState::GetState(PRUint32 aContentID,                                                               nsISupports** aState,                               nsIStatefulFrame::StateType aStateType){  nsresult rv = NS_OK;  HistoryKey key(aContentID, aStateType);  void * state = nsnull;  state = mStates.Get(&key);  if (state) {    *aState = (nsISupports *)state;  }  else {    printf("nsLayoutHistoryState::GetState, ERROR getting History state for the key\n");    *aState = nsnull;    rv = NS_ERROR_NULL_POINTER;  }  return rv;}