+val baseuri_of_file : string -> string
+
+val baseuri_of_baseuri_decl : ('a, 'b, 'c) GrafiteAst.statement -> string option
+
+ (** check whether no objects are defined below a given baseuri *)
+val is_empty: string -> bool
+
+(** removes a file if it exists *)
+val safe_remove: string -> unit
+