diff --git a/ecore.py b/ecore.py
index <HASH>..<HASH> 100644
--- a/ecore.py
+++ b/ecore.py
@@ -1,8 +1,17 @@
+"""Support for generation for models based on pyecore."""
+
+
 class ModelTypeMixin:
-    """Implements the model filter by returning all elements of a certain element type."""
+    """
+    Implements the model filter by returning all elements of a certain element type.
+    
+    Use this mixin to add the model type iteration faility to another generator task class.
+    
+    Attributes:
+        element_type: Ecore type to be searched in model and to be iterated over.
+    """
 
     element_type = None
 
     def filtered_elements(self, model):
-        # TODO: yield from model.elements.where(isinstance(e, self.element_type))
-        yield from ()
+        return (e for e in model.eAllContents() if isinstance(e, self.element_type))
diff --git a/generator.py b/generator.py
index <HASH>..<HASH> 100644
--- a/generator.py
+++ b/generator.py
@@ -1,3 +1,4 @@
+"""Small framework for multifile generation on top of another template code generator."""
 import logging
 import os
 
diff --git a/jinja.py b/jinja.py
index <HASH>..<HASH> 100644
--- a/jinja.py
+++ b/jinja.py
@@ -1,3 +1,4 @@
+"""Jinja2 support for multifile generation."""
 import jinja2
 
 from pygen.generator import TemplateGenerator, TemplateFileTask
implemented and tested ecore model type filter mixin