}
  }

  /**
   * Incorporate additional requirements into an existing requirements object.
   *
   * @param requirements the existing requirements object
   * @param moreRequirements more requirements to incorporate
   * @param source the source of the additional requirements (used only for error reporting)
   * @return the existing requirements object, modified to include the additional requirements

 *     unless it is constrained by using a method like {@link #nodeOrder}, or the builder is
 *     constructed based on an existing {@code ValueGraph} using {@link #from(ValueGraph)}.
 * @param <V> The most general value type this builder will support. This is normally {@code Object}
 *     unless the builder is constructed based on an existing {@code Graph} using {@link
 *     #from(ValueGraph)}.
 * @since 20.0
 */
@Beta
@ElementTypesAreNonnullByDefault

            int indexOf = mojos.indexOf(mojoDescriptor);

            existing = mojos.get(indexOf);
        }

        if (existing != null) {
            throw new DuplicateMojoDescriptorException(
                    getGoalPrefix(),
                    mojoDescriptor.getGoal(),
                    existing.getImplementation(),
                    mojoDescriptor.getImplementation());
        } else {

   *
   * <p>If {@code range} {@linkplain Range#isEmpty() is empty}, then this is a no-op.
   */
  void put(Range<K> range, V value);

  /**
   * Maps a range to a specified value, coalescing this range with any existing ranges with the same
   * value that are {@linkplain Range#isConnected connected} to this range.
   *
   * <p>The behavior of {@link #get(Comparable) get(k)} after calling this method is identical to

Releasing
=========

### Prerequisite: Sonatype (Maven Central) Account

Create an account on the [Sonatype issues site][sonatype_issues]. Ask an existing publisher to open
an issue requesting publishing permissions for `com.squareup` projects.


Cutting a Release
-----------------

1. Update `CHANGELOG.md`.

2. Set versions:

    ```
    export RELEASE_VERSION=X.Y.Z
    export NEXT_VERSION=X.Y.Z-SNAPSHOT
    ```

- [ ] New feature (non-breaking change which adds functionality)
- [ ] Optimization (provides speedup with no functional changes)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Checklist:
- [ ] Fixes a regression (If yes, please add `commit-id` or `PR #` here)
- [ ] Unit tests added/updated
- [ ] Internal documentation updated

 *
 */
public interface MavenExecutionRequestPopulator {
    /**
     * Copies the values from the given toolchains into the specified execution request. This method will replace any
     * existing values in the execution request that are controlled by the toolchains. Hence, it is expected that this
     * method is called on a new/empty execution request before the caller mutates it to fit its needs.
     *

     * found, the existing values are replaced.
     */
    operator fun set(
      name: String,
      value: Date,
    ) = set(name, value.toHttpDateString())

    /**
     * Set a field with the specified instant. If the field is not found, it is added. If the field
     * is found, the existing values are replaced.
     */

    // next map.get()
    when(backingMap.get(KEY)).thenReturn(existingZero);
    // since get returned zero, try a replace; that fails due to a simulated race
    when(backingMap.replace(eq(KEY), eq(existingZero), isA(AtomicInteger.class))).thenReturn(false);
    when(backingMap.putIfAbsent(eq(KEY), isA(AtomicInteger.class))).thenReturn(existing);

    // another map.get()

    }

    @Override
    public Path locatePom(Path projectDirectory) {
        // Note that the ModelProcessor#locatePom never returns null
        // while the ModelParser#locatePom needs to return an existing path!
        Path pom = modelParsers.stream()
                .map(m -> m.locate(projectDirectory)
                        .map(org.apache.maven.api.services.Source::getPath)
                        .orElse(null))