code: def remove_extension(self, ext=None):
          
          if ext is None:
              ext = list(self.get_extensions())
          if type(ext) is str:
              ext = [ext]
  
          for ee in ext:
              try:
                  del self.__dict__[ee]
              except KeyError:
                  for exinstancename, exdata in zip(
                          self.get_extensions(data=False),
                          self.get_extensions(data=True)):
                      if exdata.name == ee:
                          del self.__dict__[exinstancename]
              finally:
                  self.meta._add_modify("Removed extension {}".format(ee))
  
          return self
docs: Remove extension from IOSystem
  
          For single Extensions the same can be achieved with del
          IOSystem_name.Extension_name
  
          Parameters
          ----------
          ext : string or list, optional
              The extension to remove, this can be given as the name of the
              instance or of Extension.name (the latter will be checked if no
              instance was found)
              If ext is None (default) all Extensions will be removed