parameters: (self, extension)
docstring: Adds an extension after the environment was created.
  
          .. versionadded:: 2.5
docstring_summary: Adds an extension after the environment was created.
docstring_tokens: Adds an extension after the environment was created .
function: def add_extension(self, extension):
          """Adds an extension after the environment was created.
  
          .. versionadded:: 2.5
          """
          self.extensions.update(load_extensions(self, [extension]))
function_tokens: def add_extension ( self , extension ) : self . extensions . update ( load_extensions ( self , [ extension ] ) )