parameters: (self)
return_statement: return result
docstring: next implementation.
  
          Returns:
              The next oldest frame.
docstring_summary: next implementation.
docstring_tokens: next implementation .
function: def next(self):
          """next implementation.
  
          Returns:
              The next oldest frame."""
  
          result = self.frame
          if result is None:
              raise StopIteration
          self.frame = result.older()
          return result
function_tokens: def next ( self ) : result = self . frame if result is None : raise StopIteration self . frame = result . older ( ) return result