0,
              size,
              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);
                return comparator.compare(e1.getKey(), e2.getKey());
              });
          // requireNonNull is safe because the first `size` elements have been filled in.

      stream.defaultReadObject();
      factory = (Supplier<? extends Collection<V>>) requireNonNull(stream.readObject());
      Map<K, Collection<V>> map = (Map<K, Collection<V>>) requireNonNull(stream.readObject());
      setMap(map);
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**

     * @since 4.0.0
     */
    public void addSourceRoot(@Nonnull ProjectScope scope, @Nonnull Language language, @Nonnull Path directory) {
        directory = getBaseDirectory()
                .resolve(Objects.requireNonNull(directory, "directory cannot be null"))
                .normalize();
        addSourceRoot(new DefaultSourceRoot(scope, language, directory));
    }

    /**

        ImmutableList<AbstractFuture<T>> delegates, int inputFutureIndex) {
      /*
       * requireNonNull is safe because we accepted an Iterable of non-null Future instances, and we
       * don't overwrite an element in the array until after reading it.
       */
      ListenableFuture<? extends T> inputFuture = requireNonNull(inputFutures[inputFutureIndex]);
      // Null out our reference to this future, so it can be GCed

        if (!hasNext()) {
          throw new NoSuchElementException();
        }
        /*
         * requireNonNull is safe because our callers always pass non-null arguments. Each element
         * of the array becomes null only when we iterate past it and then clear it.
         */
        I result = requireNonNull(elements[index]);
        elements[index] = null;
        index++;
        return result;
      }
    };

        String artifactId = parent.getArtifactId();
        String version = parent.getVersion();

        ModelResolver modelResolver = request.getModelResolver();
        Objects.requireNonNull(
                modelResolver,
                String.format(
                        "request.modelResolver cannot be null (parent POM %s and POM %s)",