question: private Object [ ] initializeCallerHierarchyRoots ( Map < String , Map < String , Set < JsonElement > > > callerMap ) { List < TreeElement < SourceMethodNode , SourceMethodNode > > roots = new ArrayList < TreeElement < SourceMethodNode , SourceMethodNode > > ( ) ; CallerHierarchy callerHierarchy = ( CallerHierarchy ) fInput ; SourceMethodNode rootNode = callerHierarchy . getRoot ( ) ; Set < SourceMethodNode > processedNodes = new HashSet < SourceMethodNode > ( ) ; TreeElement < SourceMethodNode , SourceMethodNode > root = initializeCallerHierarchy ( rootNode , processedNodes , callerMap ) ; return new Object [ ] { root } ; }
target:  Creates tree elements for the caller hierarchy outline view. Returns the root elements.