anchor.diff:  
             %% Who are we working with?  This is the object in question, i.e., for
             %% /<type>/<id> this is <id>
  -          authz_id :: binary(),
  +          authz_id :: auth_id(),
   
             %% What kind of resource are we talking about here?
  -          request_type :: entity_type(),
  +          request_type :: auth_type(),
   
             %% What is the ACL on the resource?
             acl :: term(),
  
positive.code: %% a function declaration so breaks all of our behavior callbacks.
  -include_lib("webmachine/include/wm_reqdata.hrl").
  -include_lib("mixer/include/mixer.hrl").
  
  -type permission() :: create | read | update | delete | grant.
  -type entity_type() :: actor | group | container | object.
  
  %% Share resource state shared by all heimdall resource modules
  %%
  
negative.code: 
            %% What member type are we checking for?  This will always be an actor or
            %% a group
            member_type :: auth_type(),
  
            %% What's the ID of the member
            member_id :: auth_id(),
  
            %% Who's asking?
            requestor_id :: auth_id(),
  
            %% Which module is handling this request?
            module :: atom()
  