presto-main/src/main/java/io/prestosql/sql/relational/SpecialForm.java/SpecialForm/equals
class SpecialForm:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        SpecialForm that = (SpecialForm) o;
        return form == that.form &&
                Objects.equals(returnType, that.returnType) &&
                Objects.equals(arguments, that.arguments);
    }