code: public static boolean isBuildable(ClassRef ref) {
          if (BuilderContextManager.getContext().getBuildableRepository().isBuildable(ref)) {
              return true;
          }
  
          String builderFQCN = ref.getDefinition().getFullyQualifiedName() + "Builder";
          TypeDef builder = BuilderContextManager.getContext().getDefinitionRepository().getDefinition(builderFQCN);
          if (builder == null) {
              return false;
          }
  
          return builder.getMethods()
                  .stream()
                  .filter(m -> "build".equals(m.getName()))
                  .filter(m -> m.getReturnType().isAssignableFrom(ref))
                  .count() > 0;
      }
docs: Checks if {@link ClassRef} is buildable.
  @param ref       The reference.
  @return          True if buildable repository contains the ref or builder for the reference is present.