check for undefined udded for bioentity type

frontend-js/src/main/js/map/data/BioEntity.js

@@ -92,6 +92,9 @@ BioEntity.prototype.getDescription = function() {
 };
 
 BioEntity.prototype.setType = function(type) {
+  if (type === undefined) {
+    throw new Error("type cannot be undefined");
+  }
   this._type = type;
 };
 
@@ -125,5 +128,4 @@ BioEntity.prototype.setReferences = function(references) {
   this.references = references;
 };
 
-
 module.exports = BioEntity;