Compilation fails with a simple code

Hello,
I started to write couchbase client using java sdk.

I looked the following url and test a tiny code.

http://docs.couchbase.com/developer/java-2.1/java-intro.html

import com.couchbase.client.java.Cluster;
import com.couchbase.client.java.CouchbaseCluster;
import com.couchbase.client.java.Bucket;

import com.couchbase.client.java.document.JsonDocument;
import com.couchbase.client.java.document.json.JsonObject;

class CouchbaseExample
{
    public static void main(String args[])
    {
	Cluster cluster = CouchbaseCluster.create("172.17.0.3");
	// Open the default bucket and the "beer-sample" one
	Bucket bucket = cluster.openBucket("beer-sample");

	JsonDocument walter = bucket.get("walter");
	System.out.println("Found: " + walter.getString("firstname"));

	cluster.disconnect();
    }
}
$ mvn compile

[ERROR] /home/xxxx/java/cb-example/src/main/java/newtech/CouchbaseExample.java:[17,46] cannot find symbol
  symbol:   method getString(java.lang.String)
  location: variable walter of type com.couchbase.client.java.document.JsonDocument

What am I wrong with my code ?

Thanks !

It is typo in the docs. It should be walter.content().getString("firstname")

Yes, it worked fine with your suggestion.

Thanks !