src/main/java/com/alipay/remoting/rpc/RpcClient.java
public void enableConnHeartbeat(Url url) {
        if (null != url) {
            this.connectionManager.enableHeartbeat(this.connectionManager.get(url.getUniqueKey()));
        }
    }
public void enableConnHeartbeat(Url url) {
        if (null != url) {
            this.connectionManager.enableHeartbeat(this.connectionManager.get(url.getUniqueKey()));
        }
    }
Enable heart beat for a certain connection.
If this {@link Url} not connected, then do nothing.
<p>
Notice: this method takes no effect on a stand alone connection.

@param url