code: public @NotNull <T> Optional<T> findOptional(@NotNull RowMapper<T> rowMapper, @NotNull @SQL String sql, Object... args) {
          return findOptional(rowMapper, SqlQuery.query(sql, args));
      }
docs: Find a unique result from database, using given {@link RowMapper} to convert row. Returns empty if
  there are no results or if single null result is returned.
  
  @throws NonUniqueResultException if there are multiple result rows