Document the :hide: hack

Author: fayazkhan

docs/initialize.rst

@@ -132,6 +132,7 @@ tree management and finally call manually a rebuild of the tree once at the end:
 .. testcode::
     :hide:
 
+    # This is some more setup code.
     from flask import Flask
 
     class MyModelTree(db.Model, BaseNestedSets):

docs/tut_flask.rst

@@ -47,6 +47,7 @@ Add data to table with tree.
 .. testcode::
     :hide:
 
+    # This is some more setup code.
     app.app_context().push()
 
 .. testcode::

sqlalchemy_mptt/mixins.py

@@ -55,6 +55,7 @@ def __repr__(self):
     .. testcode::
         :hide:
 
+        # This is some more setup code.
         Base.metadata.create_all(engine)
         node = Tree()
         session.add(node)