code: def parse(self, scope):
          
          self.keyframe, = [
              e[0] if isinstance(e, tuple) else e for e in self.tokens
              if str(e).strip()
          ]
          self.subparse = False
          return self
docs: Parse node.
          args:
              scope (Scope): Current scope
          raises:
              SyntaxError
          returns:
              self