PRInt32 var; var = c->match.mRule->LookupSymbol(aVariable);
PRInt32 var = aThis->mRules.LookupSymbol(PromiseFlatString(aVariable).get());
nsXULTemplateBuilder::IsVarInSet(nsXULTemplateBuilder* aThis,                                 const nsAReadableString& aVariable,                                 void* aClosure){    IsVarInSetClosure* c = NS_STATIC_CAST(IsVarInSetClosure*, aClosure);    PRInt32 var;    var = c->match.mRule->LookupSymbol(aVariable);    // No variable; treat as a variable with no substitution. (This    // shouldn't ever happen, really...)    if (! var)        return;    // See if this was one of the variables that was modified. If it    // *was*, then this attribute *will* be impacted by the modified    // variable set...    c->result = c->result || c->modifiedVars.Contains(var);}