src/Pure/PIDE/document.scala

 
     def node_name: Node.Name
     def is_theory: Boolean = node_name.is_theory
     override def toString: String = node_name.toString
 
-    def try_get_text(range: Text.Range): Option[String]
+    def get_text(range: Text.Range): Option[String]
 
     def node_required: Boolean
     def get_blob: Option[Blob]
     def bibtex_entries: List[Text.Info[String]]