return this;
    }

    @Override
    public DefaultProjectBuildingRequest setRepositoryMerging(RepositoryMerging repositoryMerging) {
        this.repositoryMerging = Objects.requireNonNull(repositoryMerging, "repositoryMerging cannot be null");
        return this;
    }

    @Override
    public RepositoryMerging getRepositoryMerging() {
        return repositoryMerging;
    }

     * @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));
    }

    /**

        this.set = true;
        this.value = value;
      }

      T get() {
        /*
         * requireNonNull is safe because we call get() only if we've previously called set().
         *
         * (For further discussion of nullness, see the comment above the method.)
         */
        return requireNonNull(value);
      }
    }
    OptionalState state = new OptionalState();

          valueItr = entry.getValue().iterator();
        }
        /*
         * requireNonNull is safe: The first call to this method always enters the !hasNext() case
         * and populates currentKey, after which it's never cleared.
         */
        return immutableEntry(requireNonNull(currentKey), valueItr.next());
      }
    };
  }

  @Override
  @GwtIncompatible("Spliterator")

   * objects come from factory methods that are themselves {@code @Nullable}. In reality neither the
   * array nor its contents can be null, but it is not useful to force the use of {@code
   * requireNonNull} or the like just to assert that.
   *
   * <p>{@code EqualsTester} will always check that every object it is given returns false from

        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

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.Iterators.peekingIterator;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.Objects.requireNonNull;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.CharMatcher;

      case 0:
        return of();
      case 1:
        /*
         * requireNonNull is safe because the callers promise to put non-null objects in the first
         * `length` array elements.
         */
        @SuppressWarnings("unchecked") // our callers put only E instances into the array
        E onlyElement = (E) requireNonNull(elements[0]);
        return of(onlyElement);
      default:
        /*

        this.set = true;
        this.value = value;
      }

      T get() {
        /*
         * requireNonNull is safe because we call get() only if we've previously called set().
         *
         * (For further discussion of nullness, see the comment above the method.)
         */
        return requireNonNull(value);
      }
    }
    OptionalState state = new OptionalState();

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.Arrays.stream;
import static java.util.Objects.requireNonNull;
import static java.util.stream.Stream.concat;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Converter;