presto-parser/src/main/java/io/prestosql/sql/tree/Except.java/Except/equals
class Except:    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) {
            return true;
        }
        if ((obj == null) || (getClass() != obj.getClass())) {
            return false;
        }
        Except o = (Except) obj;
        return Objects.equals(left, o.left) &&
                Objects.equals(right, o.right) &&
                Objects.equals(isDistinct(), o.isDistinct());
    }