return MoreObjects.toStringHelper(this).addValue(callback).toString();
    }
  }

  /**
   * Returns the result of the input {@code Future}, which must have already completed.
   *
   * <p>The benefits of this method are twofold. First, the name "getDone" suggests to readers that
   * the {@code Future} is already done. Second, if buggy code calls {@code getDone} on a {@code

      tmp[5 - i] = hex.charAt(c & 0xF);
      c = (char) (c >> 4);
    }
    return String.copyValueOf(tmp);
  }

  // Fast matchers

  /** A matcher for which precomputation will not yield any significant benefit. */
  abstract static class FastMatcher extends CharMatcher {

    @Override
    public final CharMatcher precomputed() {
      return this;
    }

    @Override
    public CharMatcher negate() {

    the entire connection to fail.
 *  Fix: Don’t crash on unexpected charsets in the logging interceptor.
 *  Fix: `OkHttpClient` is now non-final for the benefit of mocking frameworks.
    Mocking sophisticated classes like `OkHttpClient` is fragile and you
    shouldn’t do it. But if that’s how you want to live your life we won’t stand
    in your way!


## Version 3.0.1