parameters: (self, id, filename)
docstring: Retrieves common corresponding to id. Returns a 404 response if
          common is not found.
docstring_summary: Retrieves common corresponding to id. Returns a 404 response if
          common is not found.
docstring_tokens: Retrieves common corresponding to id . Returns a 404 response if common is not found .
function: def get(self, id, filename):
          '''
          Retrieves common corresponding to id. Returns a 404 response if
          common is not found.
          '''
  
          common = CommonManager.get_common(id)
          if common:
              self.filename = filename
              self.on_common_found(common, id)
          else:
              self.return_failure("Common not found.", 404)
function_tokens: def get ( self , id , filename ) : common = CommonManager . get_common ( id ) if common : self . filename = filename self . on_common_found ( common , id ) else : self . return_failure ( "Common not found." , 404 )