@Override
  public String toString() {
    Connection myCon = connection;
    if (myCon != null) {
      return "Pooled Connection to " + endpoint + ": " + myCon;
    } else {
      return "Pooled Connection to " + endpoint + ": Connection[DESTROYED]";
    }
  }
Return true if the connection has been idle long enough to expire.
geode-core/src/main/java/org/apache/geode/cache/client/internal/pooling/PooledConnection.java