code: @Override
      public BitemporalMapper build(String field) {
          return new BitemporalMapper(field, validated, vtFrom, vtTo, ttFrom, ttTo, pattern, nowValue);
      }
docs: Returns the {@link BitemporalMapper} represented by this {@link MapperBuilder}.
  
  @param field the name of the field to be built
  @return the {@link BitemporalMapper} represented by this