R result = (R) finalAccum;
        assertEquivalent(expectedResult, result);
      }
      assertEquivalent(expectedResult, collector.finisher().apply(finalAccum));
    }
  }

  private void assertEquivalent(R expected, R actual) {
    assertTrue(
        "Expected " + expected + " got " + actual + " modulo equivalence " + equivalence,

        R result = (R) finalAccum;
        assertEquivalent(expectedResult, result);
      }
      assertEquivalent(expectedResult, collector.finisher().apply(finalAccum));
    }
  }

  private void assertEquivalent(R expected, R actual) {
    assertTrue(
        "Expected " + expected + " got " + actual + " modulo equivalence " + equivalence,

```

### Task Runner Logging 

This logs task enqueues, starts, and finishes.

```
[2020-01-01 00:00:00] Q10000 scheduled after   0 µs: OkHttp ConnectionPool
[2020-01-01 00:00:00] Q10000 starting              : OkHttp ConnectionPool
[2020-01-01 00:00:00] Q10000 run again after 300 s : OkHttp ConnectionPool
[2020-01-01 00:00:00] Q10000 finished run in   1 ms: OkHttp ConnectionPool

Then you go to the counter 🔀, to the initial task that is now finished ⏯, pick the burgers, say thanks and take them to the table. That finishes that step / task of interaction with the counter ⏹. That in turn, creates a new task, of "eating burgers" 🔀 ⏯, but the previous one of "getting burgers" is finished ⏹.

### Parallel Burgers { #parallel-burgers }

Now let's imagine these aren't "Concurrent Burgers", but "Parallel Burgers".

Because this code is executed before the application **starts** taking requests, and right after it **finishes** handling requests, it covers the whole application **lifespan** (the word "lifespan" will be important in a second 😉).

      byteCount: Long,
    ) {
      assertLockNotHeld()

      var remainingByteCount = byteCount

      while (remainingByteCount > 0L) {
        val finished: Boolean
        val flowControlError: Boolean
        withLock {
          finished = this.finished
          flowControlError = remainingByteCount + readBuffer.size > maxByteCount
        }

            deflater.setInput(data, offset, length);
            deflater.finish();

            ByteArrayOutputStream baos = new ByteArrayOutputStream(length);
            byte[] buffer = new byte[1024];

            while (!deflater.finished()) {
                int compressedSize = deflater.deflate(buffer);
                baos.write(buffer, 0, compressedSize);
            }

                    // Process finished normally.
                    final int exitValue = p.exitValue();
                    if (exitValue != 0) {
                        logger.warn("{} failed (exit code:{}): {}", getName(), exitValue, commandList);
                    }

                    if (logger.isDebugEnabled()) {
                        logger.debug("{} is finished with exit code {}.", getName(), exitValue);

      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 run again after  50 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 run again after 150 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
    )
  }

  /** Used by [AsyncCall.run] to signal completion. */
  internal fun finished(call: AsyncCall) {
    call.callsPerHost.decrementAndGet()
    finished(runningAsyncCalls, call)
  }

  /** Used by [Call.execute] to signal completion. */
  internal fun finished(call: RealCall) {
    finished(runningSyncCalls, call)
  }

  private fun <T> finished(
    calls: Deque<T>,
    call: T,
  ) {