h3. Plugins need a specific metadata model

Each application will have its own model for plugins. Much of this model will be common across applications but there will always be issues specific to a particular applications’s plugins. Some of the issues that need to be taken into consideration:

* Plugin dependencies

    public Builder<E> addAll(Iterator<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    /**
     * If the specified collection is backed by an ObjectCountHashMap, it will be much more
     * efficient to iterate over it by index rather than an entry iterator, which will need to
     * allocate an object for each entry, so we check for that.
     */

    assertThrows(IndexOutOfBoundsException.class, () -> iia3.subArray(1, 4));
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {

   * once after loading completes). Much internal cache management is performed at the segment
   * granularity. For example, access queues and write queues are kept per segment when they are
   * required by the selected eviction algorithm. As such, when writing unit tests it is not

And we can add a list of `dependencies` that will be added to all the *path operations* in the router and will be executed/solved for each request made to them.

/// tip

Note that, much like [dependencies in *path operation decorators*](dependencies/dependencies-in-path-operation-decorators.md), no value will be passed to your *path operation function*.

///

The end result is that the item paths are now:

    assertThrows(IndexOutOfBoundsException.class, () -> iia3.subArray(1, 4));
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {

   * equivalent (except in the case of overflow) to the call {@code
   * addAll(Collections.nCopies(element, occurrences))}, which would presumably perform much more
   * poorly.
   *
   * @param element the element to add occurrences of; may be null only if explicitly allowed by the
   *     implementation

   * equivalent (except in the case of overflow) to the call {@code
   * addAll(Collections.nCopies(element, occurrences))}, which would presumably perform much more
   * poorly.
   *
   * @param element the element to add occurrences of; may be null only if explicitly allowed by the
   *     implementation

    assertThat((long) arraysDim1 * arraysDim2).isNotEqualTo((long) (arraysDim1 * arraysDim2));

    char[][] arrays = new char[arraysDim1][];
    // it's shared to avoid using too much memory in tests
    char[] sharedArray = new char[arraysDim2];
    Arrays.fill(arrays, sharedArray);

    try {
      Chars.concat(arrays);
      fail();
    } catch (IllegalArgumentException expected) {

    return -1;
  }

  /**
   * Returns the start position of the first occurrence of the specified {@code target} within
   * {@code array}, or {@code -1} if there is no such occurrence.
   *
   * <p>More formally, returns the lowest index {@code i} such that {@code Arrays.copyOfRange(array,
   * i, i + target.length)} contains exactly the same elements as {@code target}.
   *