langchain/indexes/vectorstore.py/VectorstoreIndexCreator/from_loaders
class VectorstoreIndexCreator:    def from_loaders(self, loaders: List[BaseLoader]) -> VectorStoreIndexWrapper:
        """Create a vectorstore index from loaders."""
        docs = []
        for loader in loaders:
            docs.extend(loader.load())
        return self.from_documents(docs)