code: def add_identity(self,item_name,item_category=None,item_type=None):
          
          return DiscoIdentity(self,item_name,item_category,item_type)
docs: Add an identity to the `DiscoInfo` object.
  
          :Parameters:
              - `item_name`: name of the item.
              - `item_category`: category of the item.
              - `item_type`: type of the item.
          :Types:
              - `item_name`: `unicode`
              - `item_category`: `unicode`
              - `item_type`: `unicode`
  
          :returns: the identity created.
          :returntype: `DiscoIdentity`