* of the <i>next</i> request. I.e., if an expensive task arrives at an idle RateLimiter, it will be
 * granted immediately, but it is the <i>next</i> request that will experience extra throttling,
 * thus paying for the cost of the expensive task.
 *
 * @author Dimitris Andreou
 * @since 13.0
 */

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003_py310.py hl[16,19] *}

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols

   * same value those two ranges will be coalesced.
   *
   * <p><b>Note:</b> coalescing requires calling {@code .equals()} on any connected values, which
   * may be expensive depending on the value type. Using this method on range maps with large values
   * such as {@link Collection} types is discouraged.
   *
   * @since 22.0
   */
  void putCoalescing(Range<K> range, V value);

    testBytes(3, EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
  }

  /**
   * Tests that round tripping of a sample of four byte permutations work. All permutations are
   * prohibitively expensive to test for automated runs. This method tests specific four-byte cases.
   */
  public void testIsWellFormed_4BytesSamples() {
    // Valid 4 byte.
    assertWellFormed(0xF0, 0xA4, 0xAD, 0xA2);
    // Bad trailing bytes

### Performance Optimizations
- **Caching** - Bean descriptors and reflection metadata are cached for improved performance
- **Lazy initialization** - Resources and expensive operations are initialized only when needed  
- **Memory efficient** - Specialized collections like `LruHashMap` and `ArrayMap` for memory-conscious applications

    CountingRemovalListener<Integer, Integer> removalListener = countingRemovalListener();
    IdentityLoader<Integer> loader = identityLoader();

    // Even numbers are free, odd are too expensive
    Weigher<Integer, Integer> evensOnly = (k, v) -> k % 2;

    LoadingCache<Integer, Integer> cache =
        CacheBuilder.newBuilder()
            .concurrencyLevel(1)
            .maximumWeight(0)

// simply converts positional arguments to NewReader() into a
// more flexible way to provide optional inputs. This is currently
// used by the FanOut API call mostly to disable expensive md5sum
// calculation repeatedly under hash.Reader.
type Options struct {
	MD5Hex     string
	SHA256Hex  string
	Size       int64
	ActualSize int64
	DisableMD5 bool
	ForceMD5   []byte
}

   * is {@code 60}, and the concurrency level is {@code 8}, then eight segments are created, each
   * having a hash table of size eight. Providing a large enough estimate at construction time
   * avoids the need for expensive resizing operations later, but setting this value unnecessarily
   * high wastes memory.
   *
   * @throws IllegalArgumentException if {@code initialCapacity} is negative

   * is {@code 60}, and the concurrency level is {@code 8}, then eight segments are created, each
   * having a hash table of size eight. Providing a large enough estimate at construction time
   * avoids the need for expensive resizing operations later, but setting this value unnecessarily
   * high wastes memory.
   *
   * @throws IllegalArgumentException if {@code initialCapacity} is negative