default <T> This registerRowMapper(GenericType<T> type, RowMapper<T> mapper) {
        return configure(RowMappers.class, c -> c.register(type, mapper));
    }
Convenience method for {@code getConfig(RowMappers.class).register(type, mapper)}

@param <T>    the type
@param type   to match
@param mapper row mapper
@return this
core/src/main/java/org/jdbi/v3/core/config/Configurable.java