*
   * <p>Since Strings are immutable and built into the jdk we can optimize some operations
   *
   * <ul>
   *   <li>use {@link StringReader} instead of {@link CharSequenceReader}. It is faster since it can
   *       use {@link String#getChars(int, int, char[], int)} instead of copying characters one by
   *       one with {@link CharSequence#charAt(int)}.

   * moved to index "distance", and the element at index {@code i} ends up at index {@code (distance
   * + i) mod array.length}. This is equivalent to {@code Collections.rotate(Chars.asList(array),
   * distance)}, but is considerably faster and avoids allocation and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @since 32.0.0
   */
  public static void rotate(char[] array, int distance) {

   * moved to index "distance", and the element at index {@code i} ends up at index {@code (distance
   * + i) mod array.length}. This is equivalent to {@code Collections.rotate(Shorts.asList(array),
   * distance)}, but is considerably faster and avoids allocation and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @since 32.0.0
   */
  public static void rotate(short[] array, int distance) {

   *
   * <p>Since Strings are immutable and built into the jdk we can optimize some operations
   *
   * <ul>
   *   <li>use {@link StringReader} instead of {@link CharSequenceReader}. It is faster since it can
   *       use {@link String#getChars(int, int, char[], int)} instead of copying characters one by
   *       one with {@link CharSequence#charAt(int)}.

   * moved to index "distance", and the element at index {@code i} ends up at index {@code (distance
   * + i) mod array.length}. This is equivalent to {@code Collections.rotate(Shorts.asList(array),
   * distance)}, but is considerably faster and avoids allocation and garbage collection.
   *
   * <p>The provided "distance" may be negative, which will rotate left.
   *
   * @since 32.0.0
   */
  public static void rotate(short[] array, int distance) {

internal fun <T> List<T>.toImmutableList(): List<T> =
  when {
    this.isEmpty() -> emptyList()
    this.size == 1 -> Collections.singletonList(this[0])
    // Collection.toArray returns Object[] (covariant).
    // It is faster than creating real T[] via reflection (Arrays.copyOf).
    else -> (this as java.util.Collection<*>).toArray().asList().unmodifiable() as List<T>
  }

/** Returns an immutable list containing [elements]. */
@SafeVarargs

└── src/test/java/      # Comprehensive test suite
```

## 📊 Performance Metrics

CoreLib 0.7.0 includes significant performance improvements through Java 21 optimizations:

- **5-15% faster** type conversions with pattern matching and switch expressions
- **Reduced memory allocation** in collection operations and bean copying
- **Improved reflection performance** with cached descriptors and optimized field access

     * found, the existing values are replaced.
     */
    operator fun set(
      name: String,
      value: String,
    ) = commonSet(name, value)

    /** Equivalent to `build().get(name)`, but potentially faster. */
    operator fun get(name: String): String? = commonGet(name)

    fun build(): Headers = commonBuild()
  }

  companion object {
    /** Empty headers. */
    @JvmField

import java.util.concurrent.Executor;
import org.jspecify.annotations.Nullable;

/** Implementations of {@code Futures.transform*}. */
@GwtCompatible
// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
@SuppressWarnings("ShortCircuitBoolean")
abstract class AbstractTransformFuture<
        I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>

#      Ex. disk_cache -- Use a local cache
#      Ex. public_cache -- Use TF's public cache (read-only)
#      Ex. public_cache_push -- Use TF's public cache (read and write, Googlers only)
#      Ex. rbe        -- Use RBE for faster builds (Googlers only; see below)
#      Ex. no_docker  -- Disable docker on enabled platforms
#    See full examples below for more details on these. Some other modifiers are: