presto-main/src/main/java/io/prestosql/sql/planner/optimizations/ExpressionEquivalence.java/ExpressionEquivalence/ExpressionEquivalence
class ExpressionEquivalence:    public ExpressionEquivalence(Metadata metadata, TypeAnalyzer typeAnalyzer)
    {
        this.metadata = requireNonNull(metadata, "metadata is null");
        this.typeAnalyzer = requireNonNull(typeAnalyzer, "typeAnalyzer is null");
        this.canonicalizationVisitor = new CanonicalizationVisitor(metadata);
    }