}
  }

  abstract double doGetRate();

  /**
   * Acquires a single permit from this {@code RateLimiter}, blocking until the request can be
   * granted. Tells the amount of time slept, if any.
   *
   * <p>This method is equivalent to {@code acquire(1)}.
   *
   * @return time spent sleeping to enforce rate, in seconds; 0.0 if not rate-limited

    }
  }

  abstract double doGetRate();

  /**
   * Acquires a single permit from this {@code RateLimiter}, blocking until the request can be
   * granted. Tells the amount of time slept, if any.
   *
   * <p>This method is equivalent to {@code acquire(1)}.
   *
   * @return time spent sleeping to enforce rate, in seconds; 0.0 if not rate-limited

      overWaitNanosFirstDigit = '9';
    }
    String nanosRegex = "[4-" + overWaitNanosFirstDigit + "][0-9]+";
    assertWithMessage(
            "Spent " + thread.timeSpentBlocked + " ns blocked; slept for " + toWaitMillis + " ms")
        .that(thread.exception)
        .hasMessageThat()
        .matches(
            "Waited 2 seconds \\(plus "
                + (longWait ? "3" : "1")