made it abstract class

src/main/java/nl/sander/beejava/CodeContainer.java

@@ -0,0 +1,15 @@
+package nl.sander.beejava;
+
+import nl.sander.beejava.api.CodeLine;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public abstract class CodeContainer {
+
+    protected final List<CodeLine> code = new LinkedList<>();
+
+    public List<CodeLine> getCode() {
+        return code;
+    }
+}