parameters: (self, id, filename)
docstring: Retrieves picture corresponding to id. Returns a 404 response if
          picture is not found.
docstring_summary: Retrieves picture corresponding to id. Returns a 404 response if
          picture is not found.
docstring_tokens: Retrieves picture corresponding to id . Returns a 404 response if picture is not found .
function: def get(self, id, filename):
          '''
          Retrieves picture corresponding to id. Returns a 404 response if
          picture is not found.
          '''
  
          picture = PictureManager.get_picture(id)
          if picture:
              self.filename = filename
              self.on_picture_found(picture, id)
          else:
              self.return_failure("Picture not found.", 404)
function_tokens: def get ( self , id , filename ) : picture = PictureManager . get_picture ( id ) if picture : self . filename = filename self . on_picture_found ( picture , id ) else : self . return_failure ( "Picture not found." , 404 )