code: public LazyObject optJSONObject(String key) throws LazyException{
  		LazyNode token=getOptionalFieldToken(key);
  		if(token==null)return null;
  		if(token.type==LazyNode.VALUE_NULL)return null;
  		if(token.type!=LazyNode.OBJECT)return null;
  		LazyObject obj=new LazyObject(token);
  		obj.parent=this;
  		return obj;
  	}
docs: Returns the JSON object stored in this object for the given key on null if the key doesn't exist.
  
  @param key the name of the field on this object
  @throws LazyException if the value for the given key was not an object.
  @return an object value or null if there was no such key