diff --git a/lib/HookCodeFactory.js b/lib/HookCodeFactory.js
index e327a08..c860ea0 100644
--- a/lib/HookCodeFactory.js
+++ b/lib/HookCodeFactory.js
@@ -9,7 +9,11 @@ class HookCodeFactory {
 		this.config = config;
 		this.options = undefined;
 		this._args = undefined;
-	}
+  }
+  
+  content(options) {
+    throw new Error("Abstract: should be overridden");
+  }
 
 	create(options) {
 		this.init(options);