code: def starts_variation(self) -> bool:
          
          if not self.parent or not self.parent.variations:
              return False
  
          return self.parent.variations[0] != self
docs: Checks if this node starts a variation (and can thus have a starting
          comment). The root node does not start a variation and can have no
          starting comment.
  
          For example, in ``1. e4 e5 (1... c5 2. Nf3) 2. Nf3``, the node holding
          1... c5 starts a variation.