public PredictionContext add(PredictionContext ctx) {if ( ctx==PredictionContext.EMPTY ) return PredictionContext.EMPTY;PredictionContext existing = cache.get(ctx);if ( existing!=null ) {return existing;}cache.put(ctx, ctx);return ctx;}
public PredictionContext Add(PredictionContext ctx){if (ctx == PredictionContext.EMPTY)return PredictionContext.EMPTY;PredictionContext existing = cache.Get(ctx);if (existing != null){return existing;}cache.Put(ctx, ctx);return ctx;}