docs: public Map<String, Binding<?>> linkAll() {
      assertLockHeld();
      if (linkedBindings != null) {
        return linkedBindings;
      }
      for (Binding<?> binding : bindings.values()) {
        if (!binding.isLinked()) {
          toLink.add(binding);
        }
      }
      linkRequested(); // This method throws if bindings are not resolvable/linkable.
      linkedBindings = Collections.unmodifiableMap(bindings);
      return linkedBindings;
    }