StandardSystemProperty(String key) {
    this.key = key;
  }

  /** Returns the key used to look up this system property. */
  public String key() {
    return key;
  }

  /**
   * Returns the current value for this system property by delegating to {@link
   * System#getProperty(String)}.
   *
   * <p>The value returned by this method is non-null except in rare circumstances:
   *
   * <ul>

  /**
   * Retrieves an instance of the appropriate type. The returned object may or may not be a new
   * instance, depending on the implementation.
   *
   * @return an instance of the appropriate type
   */
  @Override
  @ParametricNullness
  T get();

  /**
   * <i>May</i> return {@code true} if {@code object} is a {@code Supplier} that behaves identically
   * to this supplier.
   *

  /**
   * Returns an array size suitable for the backing array of a hash table that uses open addressing
   * with linear probing in its implementation. The returned size is the smallest power of two that
   * can hold setSize elements with the desired load factor.
   */
  @VisibleForTesting
  static int chooseTableSize(int setSize) {
    if (setSize == 1) {
      return 2;
    }

    return doAssertThrows(expectedThrowable, supplier, /* userPassedSupplier= */ true);
  }

  @CanIgnoreReturnValue
  static <T extends Throwable> T assertThrows(
      Class<T> expectedThrowable, ThrowingRunnable runnable) {
    return doAssertThrows(
        expectedThrowable,
        () -> {
          runnable.run();
          return null;
        },

    return doAssertThrows(expectedThrowable, supplier, /* userPassedSupplier= */ true);
  }

  @CanIgnoreReturnValue
  static <T extends Throwable> T assertThrows(
      Class<T> expectedThrowable, ThrowingRunnable runnable) {
    return doAssertThrows(
        expectedThrowable,
        () -> {
          runnable.run();
          return null;
        },

  private Strings() {}

  /**
   * Returns the given string if it is non-null; the empty string otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is non-null; {@code ""} if it is null
   */
  public static String nullToEmpty(@Nullable String string) {
    return Platform.nullToEmpty(string);
  }

  /**

Once the response has been received, the connection will be returned to the pool so it can be reused for a future request. Connections are evicted from the pool after a period of inactivity.

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

        clazz = enumValue.getDeclaringClass();
    try {
      return clazz.getDeclaredField(enumValue.name());
    } catch (NoSuchFieldException impossible) {
      throw new AssertionError(impossible);
    }
  }

  /**
   * Returns an optional enum constant for the given type, using {@link Enum#valueOf}. If the
   * constant does not exist, {@link Optional#absent} is returned. A common use case is for parsing

          state -> {
            Object result = state.getElement();
            return (result == NULL_PLACEHOLDER) ? null : result;
          },
          Collector.Characteristics.UNORDERED);

  /**
   * A collector that takes a stream containing exactly one element and returns that element. The
   * returned collector throws an {@code IllegalArgumentException} if the stream consists of two or

      if (bits == 32) {
        /*
         * The long returned from a 32-bit Checksum will have all 0s for its second word, so the
         * cast won't lose any information and is necessary to return a HashCode of the correct
         * size.
         */
        return HashCode.fromInt((int) value);
      } else {
        return HashCode.fromLong(value);
      }
    }
  }

  @J2ObjCIncompatible