* @since 10.0 (replacing {@code Futures.makeListenable}, which existed in 1.0)
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class JdkFutureAdapters {
  /**
   * Assigns a thread to the given {@link Future} to provide {@link ListenableFuture} functionality.
   *
   * <p><b>Warning:</b> If the input future does not already implement {@code ListenableFuture}, the

      }
      asciiDigits = result;
    }

    static int digit(char c) {
      return (c < 128) ? asciiDigits[c] : -1;
    }
  }

  /**
   * Parses the specified string as a signed decimal long value. The ASCII character {@code '-'} (
   * <code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Long#parseLong(String)}, this method returns {@code null} instead of throwing