presto-main/src/main/java/io/prestosql/operator/index/PageBufferOperator.java/PageBufferOperator/PageBufferOperator
class PageBufferOperator:    public PageBufferOperator(OperatorContext operatorContext, PageBuffer pageBuffer)
    {
        this.operatorContext = requireNonNull(operatorContext, "operatorContext is null");
        this.pageBuffer = requireNonNull(pageBuffer, "pageBuffer is null");
    }