question: private void addConnections ( Collection < Connection > connections ) throws GuacamoleException { for ( Connection connection : connections ) { APIConnectionGroup parent = retrievedGroups . get ( connection . getParentIdentifier ( ) ) ; if ( parent != null ) { Collection < APIConnection > children = parent . getChildConnections ( ) ; if ( children == null ) { children = new ArrayList < APIConnection > ( ) ; parent . setChildConnections ( children ) ; } APIConnection apiConnection = new APIConnection ( connection ) ; retrievedConnections . put ( connection . getIdentifier ( ) , apiConnection ) ; children . add ( apiConnection ) ; } else logger . debug ( "Connection \"{}\" cannot be added to the tree: parent \"{}\" does not actually exist." , connection . getIdentifier ( ) , connection . getParentIdentifier ( ) ) ; } }
target:  Adds each of the provided connections to the current tree as children of their respective parents. The parent connection groups must already be added.