try {
                return toXml(configuration, evaluator);
            } catch (ExpressionEvaluationException e) {
                throw new ComponentConfigurationException("Unable to convert configuration to xml node", e);
            }
        }

        XmlNode toXml(PlexusConfiguration config, ExpressionEvaluator evaluator) throws ExpressionEvaluationException {

     * @return the xml string representation
     * @throws XmlWriterException if an error occurs during the transformation
     * @see #fromXmlString(String)
     */
    public static String toXml(@Nonnull PluginDescriptor content) throws XmlWriterException {
        return new DefaultPluginXmlFactory().toXmlString(content);
    }

 * I'm not completely sure that this is the right choice, but it has various advantages:
 *
 * <ul>
 *   <li>An annotation named just "Suppress" might someday be treated by a non-Android tool as a
 *       suppression. This would follow the precedent of many of our annotation processors, which
 *       look for any annotation named, e.g., "GwtIncompatible," regardless of package.

     * then the path type is determined by checking if the dependency is modular.</p>
     *
     * @param types types of path where a dependency can be placed
     * @param filter filter the paths accepted by the tool which will consume the path
     * @param path path to the JAR file or output directory of the dependency
     * @return where to place the dependency, or an empty value if the placement cannot be determined

     * then the path type is determined by checking if the dependency is modular.</p>
     *
     * @param types types of path where a dependency can be placed
     * @param filter filter the paths accepted by the tool which will consume the path
     * @param path path to the JAR file or output directory of the dependency
     * @return where to place the dependency, or an empty value if the placement cannot be determined

                    toRet.add(fact.createToolchain(tm));
                }
            }

            // add default toolchain
            ToolchainPrivate tool = fact.createDefaultToolchain();
            if (tool != null) {
                toRet.add(tool);
            }
        }

        return toRet.toArray(new ToolchainPrivate[0]);
    }

    @Override

    String id();

    /**
     * Returns the name of the tool option for this path. For example, if this path type
     * is {@link JavaPathType#MODULES}, then this method returns {@code "--module-path"}.
     * The option does not include the {@linkplain JavaPathType.Modular#moduleName() module name}
     * on which it applies.
     *
     * @return the name of the tool option for this path type
     */
    @Nonnull

    return suite;
  }

  Set<String> friends;
  Set<String> enemies;

  @Override
  public void setUp() {
    friends = Sets.newHashSet("Tom", "Joe", "Dave");
    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    assertThat(m.keySet()).containsExactly("boy", "girl", "cat", "dog").inOrder();
    assertThat(m)
        .isEqualTo(ImmutableMap.of("boy", "tom", "girl", "tina", "cat", "kitty", "dog", "tommy"));

    // try in a different order
    m = COMMA_SPLITTER.withKeyValueSeparator(":").split("girl:tina,boy:tom,dog:tommy,cat:kitty");

public interface DependencyResolverRequest extends DependencyCollectorRequest {

    @Nonnull
    PathScope getPathScope();

    /**
     * Returns a filter for the types of path (class-path, module-path, …) accepted by the tool.
     * For example, if a Java tools accepts only class-path elements, then the filter should return
     * {@code true} for {@link JavaPathType#CLASSES} and {@code false} for {@link JavaPathType#MODULES}.