code: private <S> ConvertManagerTypeImpl<S> getOrCreate(Class<S> sourceType)
    {
      ConvertManagerTypeImpl<S> convertType
      = (ConvertManagerTypeImpl<S>) _convertMap.get(sourceType);
    
      if (convertType != null) {
        return convertType;
      }
      
      convertType = new ConvertManagerTypeImpl<>(sourceType);
      
      _convertMap.putIfAbsent(sourceType, convertType);
  
      return (ConvertManagerTypeImpl<S>) _convertMap.get(sourceType);
    }
docs: Returns the ConvertManagerTypeImpl for a given source type.