* ParametricNullness parametric nullness}. If a type parameter instead ranges over only non-null
   * types (or if the type is a non-variable type, like {@code String}), then code should almost
   * never use this method, preferring instead to call {@code requireNonNull} so as to benefit from
   * its runtime check.
   *

 *
 * <p>Also, if caller suppresses unchecked warnings and passes in an {@code Iterable<String>} for
 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *

- **Type safety** - Extensive use of generics and null-safe operations throughout the API
- **Resource management** - Proper handling of resources with utilities like `CloseableUtil` and `DisposableUtil`

### Key Architectural Patterns
- **Factory Pattern** - `BeanDescFactory` for creating bean descriptors, `ParameterizedClassDescFactory` for generic type handling

Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020

   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *
   * <p>The scope ID is validated against the interfaces on the machine, which requires permissions
   * under Android.
   *

        this.b = b;
        this.off = off;
        this.count = len;
        this.digest = null; /*
                             * otherwise recycled commands
                             * like writeandx will choke if session
                             * closes in between
                             */
    }

    @Override
    protected int writeParameterWordsWireFormat(final byte[] dst, int dstIndex) {

  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * ListMultimap.asMap essentially returns a Map<K, List<V>>; we just can't declare it that way.
   * Thus, calls like asMap().values().remove(someList) are safe because they are comparing a list
   * to a collection of other lists.
   */
  @SuppressWarnings("CollectionUndefinedEquality")
  public void testValuesRemove() {

  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * ListMultimap.asMap essentially returns a Map<K, List<V>>; we just can't declare it that way.
   * Thus, calls like asMap().values().remove(someList) are safe because they are comparing a list
   * to a collection of other lists.
   */
  @SuppressWarnings("CollectionUndefinedEquality")
  public void testValuesRemove() {

          }
        });
      }
    ```

### Accessing Headers ([.kt][AccessHeadersKotlin], [.java][AccessHeadersJava])

   * by the application:
   *
   * * It may be transformed by the user's interceptors. For example, an application interceptor
   *   may add headers like `User-Agent`.
   * * It may be the request generated in response to an HTTP redirect or authentication
   *   challenge. In this case the request URL may be different than the initial request URL.
   *