Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003.py hl[16,19] *}

    int removes = frequency(asList(stimuli), remove);
    if ((!features.contains(IteratorFeature.SUPPORTS_REMOVE) && removes > 1)
        || (stimuli.length >= 5 && removes > 2)) {
      // removes are the most expensive thing to test, since they often throw exceptions with stack
      // traces, so we test them a bit less aggressively
      return;
    }

    int removes = frequency(asList(stimuli), remove);
    if ((!features.contains(IteratorFeature.SUPPORTS_REMOVE) && removes > 1)
        || (stimuli.length >= 5 && removes > 2)) {
      // removes are the most expensive thing to test, since they often throw exceptions with stack
      // traces, so we test them a bit less aggressively
      return;
    }

    return Optional.absent();
  }

  /**
   * Returns the length of this source in chars, even if doing so requires opening and traversing an
   * entire stream. To avoid a potentially expensive operation, see {@link #lengthIfKnown}.
   *
   * <p>The default implementation calls {@link #lengthIfKnown} and returns the value if present. If

			done = globalScannerMetrics.time(scannerMetricTierObjSweep)
			globalExpiryState.enqueueFreeVersion(oi)
			done()
		}

		// These are rather expensive. Skip if nobody listens.
		if globalTrace.NumSubscribers(madmin.TraceScanner) > 0 {
			if len(fivs.FreeVersions) > 0 {
				res["free-versions"] = strconv.Itoa(len(fivs.FreeVersions))
			}

---

### 🛠 **Seamless IDE & CI Integration**

Gradle is built to work smoothly with a variety of Integrated Development Environments (IDEs) and Continuous Integration (CI) systems, providing extensive support for a streamlined workflow:

    assertEquals(Range.open(2, 4), Range.atMost(2).gap(closedRange));
    assertEquals(Range.open(2, 4), closedRange.gap(Range.atMost(2)));
  }

  // TODO(cpovirk): More extensive testing of gap().

  public void testSpan_general() {
    Range<Integer> range = Range.closed(4, 8);

    // separate below
    assertEquals(Range.closed(0, 8), range.span(Range.closed(0, 2)));

		}
	}
}

// TestWriterReadFromCounts tests that using io.Copy to copy into a
// bufio.Writer does not prematurely flush the buffer. For example, when
// buffering writes to a network socket, excessive network writes should be
// avoided.
func TestWriterReadFromCounts(t *testing.T) {
	var w0 writeCountingDiscard
	b0 := NewWriterSize(&w0, 1234)
	b0.WriteString(strings.Repeat("x", 1000))
	if w0 != 0 {