return mContent->QueryInterface(NS_GET_IID(nsISupports), (void **)aParent);
return mContent->QueryInterface(kISupportsIID, (void **)aParent);
nsDOMCSSAttributeDeclaration::GetParent(nsISupports **aParent){  NS_ENSURE_ARG_POINTER(aParent);  *aParent = nsnull;  if (nsnull != mContent) {    return mContent->QueryInterface(NS_GET_IID(nsISupports), (void **)aParent);  }  return NS_OK;}