private DependencyInjector dependencyInjectorOrReflective() {
        if (dependencyInjector != null) {
            return dependencyInjector;
        }
        final ReflectiveDependencyInjector reflectiveDependencyInjector = new ReflectiveDependencyInjector();
        shutdownSupports.add(ShutdownSupport.of(reflectiveDependencyInjector));
        return reflectiveDependencyInjector;
    }
Returns a list of {@link ServerPort}s which consists of distinct port numbers except for the port
{@code 0}. If there are the same port numbers with different {@link SessionProtocol}s,
their {@link SessionProtocol}s will be merged into a single {@link ServerPort} instance.
The returned list is sorted as the same order of the specified {@code ports}.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java