public interface Weigher<K, V> {

  /**
   * Returns the weight of a cache entry. There is no unit for entry weights; rather they are simply
   * relative to each other.
   *
   * @return the weight of the entry; must be non-negative
   */
  int weigh(K key, V value);

  /** Returns a {@link Weigher} that returns the given {@code constant} for every request. */
  static Weigher<Object, Object> constantWeigher(int constant) {
    return new ConstantWeigher(constant);
  }

  /** Returns a {@link Weigher} that uses the integer key as the weight. */
  static Weigher<Integer, Object> intKeyWeigher() {
    return new IntKeyWeigher();
  }

        long weightC = comparator.getProjectWeight(projectC);
        long weightX = comparator.getProjectWeight(projectX);

        // Project A should have the highest weight as it's at the root
        assertTrue(weightA > weightB, "Project A should have weight > Project B");
        assertTrue(weightA > weightC, "Project A should have weight > Project C");
        assertTrue(weightB > weightX, "Project B should have weight > Project X");

    }

    public static String key(String groupId, String artifactId, String version) {
        notBlank(groupId, "groupId can neither be null, empty nor blank");
        notBlank(artifactId, "artifactId can neither be null, empty nor blank");
        notBlank(version, "version can neither be null, empty nor blank");

        return groupId + ":" + artifactId + ":" + version;
    }

 * <ul>
 * <li>Project D: weight = 1 (no downstream dependencies)</li>
 * <li>Project B: weight = 2 (1 + max(D=1))</li>
 * <li>Project C: weight = 2 (1 + max(D=1))</li>
 * <li>Project A: weight = 3 (1 + max(B=2, C=2))</li>
 * </ul>
 * <p>Build order: A (weight=3), then B and C (weight=2, ordered by project ID), then D (weight=1)
 * <p>If projects have identical weights and IDs, the order is deterministic but may not preserve

   * array nor its contents can be null, but it is not useful to force the use of {@code
   * requireNonNull} or the like just to assert that.
   *
   * <p>{@code EqualsTester} will always check that every object it is given returns false from
   * {@code equals(null)}, so it is neither useful nor allowed to include a null value in any
   * equality group.
   */

   * non-null, it should be reported to the user should all further attempts fail.
   *
   * The two values are independent: results can contain both (recoverable error), neither
   * (success), just an exception (permanent failure), or just a plan (non-exceptional retry).
   */
  data class ConnectResult(
    val plan: Plan,
    val nextPlan: Plan? = null,

This means that, even though your API clients can only send strings as keys, as long as those strings contain pure integers, Pydantic will convert them and validate them.

And the `dict` you receive as `weights` will actually have `int` keys and `float` values.

///

## Recap { #recap }

With **FastAPI** you have the maximum flexibility provided by Pydantic models, while keeping your code simple, short and elegant.

 * ===========================
 *
 * This is UTF-8 character data. It is indexed into by b2b3 in the ranges dataset.
 *
 * Mappings may overlap.
 *
 * ASCII-Only
 * ==========
 *
 * Neither the section index nor the ranges data use bit 0x80 anywhere. That means the data is
 * strictly ASCII. This is intended to make it efficient to encode this data as a string, and to
 * index into it as a string.
 *

/// tip | 팁

JSON은 오직 `str`형 키만 지원한다는 것을 염두에 두세요.

하지만 Pydantic은 자동 데이터 변환이 있습니다.

즉, API 클라이언트가 문자열을 키로 보내더라도 해당 문자열이 순수한 정수를 포함하는한 Pydantic은 이를 변환하고 검증합니다.

그러므로 `weights`로 받은 `dict`는 실제로 `int` 키와 `float` 값을 가집니다.

///

## 요약

**FastAPI**를 사용하면 Pydantic 모델이 제공하는 최대 유연성을 확보하면서 코드를 간단하고 짧게, 그리고 우아하게 유지할 수 있습니다.

물론 아래의 이점도 있습니다:

* 편집기 지원 (자동완성이 어디서나!)