code: private void addMappers( final AbstractConfiguration configuration, final MapperType mapperType, Builder<JClassType>
              allSupportedSerializationClassBuilder, Builder<JClassType> allSupportedDeserializationClassBuilder ) throws
              UnableToCompleteException {
          Map<Class, Class> configuredMapper = mapperType.getMapperTypeConfiguration( configuration );
  
          for ( Entry<Class, Class> entry : configuredMapper.entrySet() ) {
  
              JType mappedType = findType( entry.getKey() );
              if ( null == mappedType ) {
                  continue;
              }
  
              JClassType mapperClassType = findClassType( entry.getValue() );
              if ( null == mapperClassType ) {
                  continue;
              }
  
              if ( mapperType.isKey() ) {
                  MapperInstance keyMapperInstance = getKeyInstance( mappedType, mapperClassType, mapperType.isSerializer() );
                  if ( mapperType.isSerializer() ) {
                      keySerializers.put( mappedType.getQualifiedSourceName(), keyMapperInstance );
                  } else {
                      keyDeserializers.put( mappedType.getQualifiedSourceName(), keyMapperInstance );
                  }
              } else {
                  MapperInstance mapperInstance = getInstance( mappedType, mapperClassType, mapperType.isSerializer() );
                  if ( null != mapperInstance ) {
                      if ( mapperType.isSerializer() ) {
                          serializers.put( mappedType.getQualifiedSourceName(), mapperInstance );
                          if ( null != mappedType.isClass() ) {
                              allSupportedSerializationClassBuilder.add( mappedType.isClass() );
                          }
                      } else {
                          deserializers.put( mappedType.getQualifiedSourceName(), mapperInstance );
                          if ( null != mappedType.isClass() ) {
                              allSupportedDeserializationClassBuilder.add( mappedType.isClass() );
                          }
                      }
                  }
              }
          }
      }
docs: Parse the configured serializer/deserializer configuration and put them into the corresponding map
  
  @param configuration configuration
  @param mapperType type of the mapper
  @param allSupportedSerializationClassBuilder builder aggregating all the types that have a serializer
  @param allSupportedDeserializationClassBuilder builder aggregating all the types that have a deserializer