public APIConnectionGroup getRootAPIConnectionGroup() {
        return rootAPIGroup;
    }
Returns the entire connection group tree as an APIConnectionGroup. The
returned APIConnectionGroup is the root group and will contain all
descendant connection groups and connections, arranged hierarchically.

@return
    The root connection group, containing the entire connection group
    tree and all connections.
guacamole/src/main/java/org/apache/guacamole/rest/connectiongroup/ConnectionGroupTree.java