synchronized SystemTimer getIdleConnTimer() {
    if (closed) {
      return null;
    }
    if (idleConnTimer == null) {
      idleConnTimer = new SystemTimer(getDM().getSystem());
    }
    return idleConnTimer;
  }
returns the idle connection timer, or null if the connection table is closed. guarded by a sync
on the connection table
geode-core/src/main/java/org/apache/geode/internal/tcp/ConnectionTable.java