----

== Making different flavors of a library available through capabilities

Because it is difficult to model <<feature_variants.adoc#feature_variants,optional feature variants>> as separate jars with pom metadata, libraries sometimes compose different jars with a different feature set.

   * Map.getOrDefault}</a>.
   *
   * @since 23.5 (but since 21.0 in the JRE <a
   *     href="https://github.com/google/guava#guava-google-core-libraries-for-java">flavor</a>).
   *     Note, however, that Java 8+ users can call this method with any version and flavor of
   *     Guava.
   */
  // @Override under Java 8 / API Level 24
  @CheckForNull

  /**
   * @since 21.0 (but only since 23.5 in the Android <a
   *     href="https://github.com/google/guava#guava-google-core-libraries-for-java">flavor</a>).
   *     Note, however, that Java 8+ users can call this method with any version and flavor of
   *     Guava.
   */
  @Override
  @CheckForNull
  public final V getOrDefault(@CheckForNull Object key, @CheckForNull V defaultValue) {
    /*

#   ZONE
function get-node-env() {
  # TODO(zmerlynn): Make this more reliable with retries.
  gcloud compute --project "${PROJECT}" ssh --zone "${ZONE}" "${NODE_NAMES[0]}" --command \
    "curl --fail --silent -H 'Metadata-Flavor: Google' \
      'http://metadata/computeMetadata/v1/instance/attributes/kube-env'" 2>/dev/null
}

# Read os distro information from /os/release on node.
# $1: The name of node
#
# Assumed vars:

            </tr>
            <tr>
                <td>org.gradle.nativeplatform.BuildType</td>
            </tr>
            <tr>
                <td>org.gradle.nativeplatform.Flavor</td>
            </tr>
            <tr>
                <td>org.gradle.language.assembler.AssemblerSourceSet</td>
            </tr>
            <tr>
                <td>org.gradle.language.c.CSourceSet</td>

		w.Header().Set("Upgrade", "foo")
		w.Header().Set(fakeHopHeader, "foo")
		w.Header().Add("X-Multi-Value", "foo")
		w.Header().Add("X-Multi-Value", "bar")
		http.SetCookie(w, &http.Cookie{Name: "flavor", Value: "chocolateChip"})
		w.WriteHeader(backendStatus)
		w.Write([]byte(backendResponse))
		w.Header().Set("X-Trailer", "trailer_value")
		w.Header().Set(http.TrailerPrefix+"X-Unannounced-Trailer", "unannounced_trailer_value")

If the type-safe task accessor `tasks.jar` isn't available, see the <<#configuring-plugins,configuring plugins>> section above, you can fallback to using the `tasks` container API. The Kotlin flavor of the following sample is strictly equivalent to the one using the type-safe accessor above:

.Using the `tasks` container API
====

				// curl -H "Metadata-Flavor: Google" 169.254.169.254/computeMetadata/v1/instance/service-accounts/default/identity
				opts := echo.CallOptions{
					Address: "169.254.169.254",
					Port:    echo.Port{ServicePort: 80},
					Scheme:  scheme.HTTP,
					HTTP: echo.HTTP{
						// TODO: detect which platform?
						Headers: headers.New().With("Metadata-Flavor", "Google").Build(),

     * Captures an object to be closed when a {@link ClosingFuture} pipeline is done.
     *
     * <p>For users of the {@code -jre} flavor of Guava, the object can be any {@code
     * AutoCloseable}. For users of the {@code -android} flavor, the object must be a {@code
     * Closeable}. (For more about the flavors, see <a
     * href="https://github.com/google/guava#adding-guava-to-your-build">Adding Guava to your
     * build</a>.)
     *

     * Captures an object to be closed when a {@link ClosingFuture} pipeline is done.
     *
     * <p>For users of the {@code -jre} flavor of Guava, the object can be any {@code
     * AutoCloseable}. For users of the {@code -android} flavor, the object must be a {@code
     * Closeable}. (For more about the flavors, see <a
     * href="https://github.com/google/guava#adding-guava-to-your-build">Adding Guava to your
     * build</a>.)
     *