presto-main/src/main/java/io/prestosql/operator/index/PageBuffer.java/PageBuffer/PageBuffer
class PageBuffer:    public PageBuffer(int maxBufferedPages)
    {
        checkArgument(maxBufferedPages > 0, "maxBufferedPages must be at least one");
        this.maxBufferedPages = maxBufferedPages;
        this.pages = new ArrayDeque<>(maxBufferedPages);
    }