* created for testing should have Integer node and String edge objects.
 *
 * <p>Test cases that should be handled similarly in any graph implementation are included in this
 * class. For example, testing that {@code nodes()} method returns the set of the nodes in the
 * graph. The following test cases are left for the subclasses to handle:
 *
 * <ul>

        result.put(entry.getKey(), entry.getValue());
      }
      return result;
    }

    @Override
    public SampleElements<Entry<Country, Currency>> samples() {
      return new SampleElements<>(
          mapEntry(Country.CANADA, Currency.DOLLAR),
          mapEntry(Country.CHILE, Currency.PESO),
          mapEntry(Country.UK, Currency.POUND),

 * returned.
 *
 * <p>All default instances returned by {@link #get} are generics-safe. Clients won't get type
 * errors for using {@code get(Comparator.class)} as a {@code Comparator<Foo>}, for example.
 * Immutable empty instances are returned for collection types; {@code ""} for string; {@code 0} for
 * number types; reasonable default instance for other stateless types. For mutable types, a fresh

// deliver a final empty token (which is different from a nil token).
// One could achieve the same behavior with a custom error value but
// providing one here is tidier.
// See the emptyFinalToken example for a use of this value.
var ErrFinalToken = errors.New("final token")

// Scan advances the [Scanner] to the next token, which will then be

//
//	Slice: The size specifies the length. The capacity of the slice is
//	equal to its length. A second integer argument may be provided to
//	specify a different capacity; it must be no smaller than the
//	length. For example, make([]int, 0, 10) allocates an underlying array
//	of size 10 and returns a slice of length 0 and capacity 10 that is
//	backed by this underlying array.
//	Map: An empty map is allocated with enough space to hold the

 * returned.
 *
 * <p>All default instances returned by {@link #get} are generics-safe. Clients won't get type
 * errors for using {@code get(Comparator.class)} as a {@code Comparator<Foo>}, for example.
 * Immutable empty instances are returned for collection types; {@code ""} for string; {@code 0} for
 * number types; reasonable default instance for other stateless types. For mutable types, a fresh

```

</div>

### Step 3: *path operation*を作成

#### パス

ここでの「パス」とは、最初の`/`から始まるURLの最後の部分を指します。

したがって、次のようなURLでは:

```
https://example.com/items/foo
```

...パスは次のようになります:

```
/items/foo
```

/// info | "情報"

「パス」は一般に「エンドポイント」または「ルート」とも呼ばれます。

///

APIを構築する際、「パス」は「関心事」と「リソース」を分離するための主要な方法です。

   * source Iterable, unless that Iterator is unmodifiable.
   */
  protected abstract I newTargetIterator();

  /**
   * Override this to verify anything after running a list of Stimuli.
   *
   * <p>For example, verify that calls to remove() actually removed the correct elements.
   *
   * @param elements the expected elements passed to the constructor, as mutated by {@code
   *     remove()}, {@code set()}, and {@code add()} calls

 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:
 *
 * <pre>{@code
 * Bill bill = remoteService.getLastUnpaidBill();
 *
 * // In case bug 12345 happens again we'd rather just die
 * Verify.verify(bill.status() == Status.UNPAID,

		Long: fmt.Sprintf("Analyze Istio configuration and print validation messages.\n"+
			"For more information about message codes, refer to:\n%s", url.ConfigAnalysis),
		Example: `  # Analyze the current live cluster
  istioctl analyze

  # Analyze the current live cluster for a specific revision
  istioctl analyze --revision 1-16