private void checkIdleTimeout(long idleTimeoutMillis, long elapsedMillis) {
    assertThat(elapsedMillis)
        .as("Elapsed " + elapsedMillis + " is less than idle timeout " + idleTimeoutMillis)
        .isGreaterThanOrEqualTo(idleTimeoutMillis - ALLOWABLE_ERROR_IN_MILLIS);

    assertThat(elapsedMillis)
        .as("Elapsed " + elapsedMillis + " is greater than idle timeout " + idleTimeoutMillis)
        .isLessThanOrEqualTo(idleTimeoutMillis + ALLOWABLE_ERROR_IN_MILLIS);
  }
This tests that a deadlock between connection formation and connection pool closing has been
fixed. See GEODE-4615
geode-core/src/integrationTest/java/org/apache/geode/cache/client/internal/pooling/ConnectionManagerJUnitTest.java