if s == -1 {
			s = len(fwd)
		}
		addr = fwd[:s]
	} else if fwd := r.Header.Get(xRealIP); fwd != "" {
		// X-Real-IP should only contain one IP address (the client making the
		// request).
		addr = fwd
	} else if fwd := r.Header.Get(forwarded); fwd != "" {
		// match should contain at least two elements if the protocol was
		// specified in the Forwarded header. The first element will always be

      fail("putIfAbsent(null, value) should throw");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupported() {
    try {

      fail("putIfAbsent(null, value) should throw");
    } catch (NullPointerException expected) {
    }
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupportedAndKeyAbsent() {
    try {

 *     visit(t.getGenericComponentType());
 *   }
 *   protected void visitTypeVariable(TypeVariable<?> t) {
 *     throw new IllegalArgumentException("Cannot contain type variable.");
 *   }
 *   protected void visitWildcardType(WildcardType t) {
 *     throw new IllegalArgumentException("Cannot contain wildcard type.");
 *   }
 * }.visit(type);
 * }</pre>
 *

     */
    @Nonnull
    List<Node> getNodes();

    /**
     * Returns the file paths of all dependencies, regardless on which tool option those paths should be placed.
     * The returned list may contain a mix of Java class-path, Java module-path, and other types of path elements.
     *
     * @return the paths of all dependencies
     */
    @Nonnull
    List<Path> getPaths();

    /**

          return optional.orNull();
        }
      };

  /**
   * Sets.cartesianProduct doesn't allow sets that contain null, but we want null to mean "don't
   * call the associated CacheBuilder method" - that is, get the default CacheBuilder behavior. This
   * method wraps the elements in the input sets (which may contain null) as Optionals, calls
   * Sets.cartesianProduct with those, then transforms the result to unwrap the Optionals.
   */

import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */

import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */

    @Override
    public List<String> getModelIds() {
        return modelIds;
    }

    public DefaultModelBuilderResult addModelId(String modelId) {
        // Intentionally notNull because Super POM may not contain a modelId
        Objects.requireNonNull(modelId, "modelId cannot be null");

        modelIds.add(modelId);

        return this;
    }

    @Override
    public Model getRawModel() {

  // stomped by the controller.
  // +optional
  optional AggregationRule aggregationRule = 3;
}

// ClusterRoleBinding references a ClusterRole, but not contain it.  It can reference a ClusterRole in the global namespace,
// and adds who information via Subject.
message ClusterRoleBinding {
  // Standard object's metadata.
  // +optional