code: private Source register(Source source) {
          
          /**
           * As promised, the registrar simply abstracts away internal resolvers
           * by iterating over them during the registration process.
           */
          for (Resolver resolver : resolvers) {
              resolver.register(source);
          }
          
          return source;
      }
docs: Registers a source of instances with all the internal resolvers.
  
  @param source The source to be registered.
  @return The argument source, for chaining.