langchain/graphs/networkx_graph.py/KnowledgeTriple/from_string
class KnowledgeTriple:    def from_string(cls, triple_string: str) -> "KnowledgeTriple":
        """Create a KnowledgeTriple from a string."""
        subject, predicate, object_ = triple_string.strip().split(", ")
        subject = subject[1:]
        object_ = object_[:-1]
        return cls(subject, predicate, object_)