drools-eclipse/org.drools.eclipse/src/main/java/org/drools/eclipse/editors/completion/Node.java
public Node addToken(String token) {
        Node newnode = new Node(token);
        // set the depth first
        newnode.setDepth(depth + 1);
        // add the node as a child
        newnode = addChild(newnode);
        return newnode;
    }
public Node addToken(String token) {
        Node newnode = new Node(token);
        // set the depth first
        newnode.setDepth(depth + 1);
        // add the node as a child
        newnode = addChild(newnode);
        return newnode;
    }
The method will create a new Node instance and try to add it as
a child node. If an Node with the same string token exists, the
method will return the existing node instead.
@param token
@return