presto-main/src/main/java/io/prestosql/operator/JoinOperatorInfo.java/JoinOperatorInfo/toString
class JoinOperatorInfo:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("joinType", joinType)
                .add("logHistogramProbes", logHistogramProbes)
                .add("logHistogramOutput", logHistogramOutput)
                .add("lookupSourcePositions", lookupSourcePositions)
                .toString();
    }