question: public static TypesTree createDefaultDndTypesTree ( final TypeManager typeManager ) { Preconditions . checkNotNull ( typeManager , "Error: typeManager argument can not be null" ) ; final TypesTree typesTree = CreateDragAndDropTypesTree ( typeManager ) ; typesTree . setModel ( TypesTreeModel . createDefaultModel ( typeManager ) ) ; return typesTree ; }
target:  Creates a types tree control, sets the model that includes all existing types and installs drag'n'drop support.