public String getParentIdentifier() {

        // Translate null parent to proper identifier
        String parentIdentifier = getModel().getParentIdentifier();
        if (parentIdentifier == null)
            return RootConnectionGroup.IDENTIFIER;

        return parentIdentifier;
        
    }
Returns the identifier of the parent connection group, which cannot be
null. If the parent is the root connection group, this will be
RootConnectionGroup.IDENTIFIER.

@return
    The identifier of the parent connection group.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/base/ModeledChildDirectoryObject.java