anchor.diff:  
   Implementing a factory might be preferable to a regular row mapper if:
   
  -* Multiple classes follow a similar coding pattern, and a row mapper could be
  -  implemented in a generalized format. For example, Jdbi provides a generalized
  -  <<BeanMapper>>, which maps result set columns to bean properties.
  +* The mapper implementation is generic, and could apply to multiple mapped
  +  types. For example, Jdbi provides a generalized <<BeanMapper>>, which maps
  +  columns to bean properties for any bean class.
   * The mapped type has a generic signature, and/or the mapper could be composed
     from other registered mappers. For example, Jdbi provides a
     <<Map.Entry mapping,Map.Entry<K,V> mapper>>, provided a mapper is registered
     for types `K` and `V`.
  +* You want to bundle multiple mappers into a single class.
   
   Let's take an example `Pair<L, R>` class:
   
  
positive.code: 
  ==== Row Mappers
  
  The link:{jdbidocs}/core/mapper/RowMapper.html[RowMapper^] is a functional
  interface, which maps the current row of a JDBC
  link:{jdkdocs}/java/sql/ResultSet.html[ResultSet^] to a mapped type. Row
  mappers are invoked once for each row in the result set.
  
negative.code: `UserMapper` class in the previous section) may be registered without specifying
  the mapped type:
  
  [source,java]
  ----
  handle.registerRowMapper(new UserMapper());
  ----
  