def load_document(self, document_url: str) -> Document:
        """
        Load a single document from Firestore.

        Args:
            document_url (str): The absolute path to the Firestore document to read.

        Returns:
            Document: A Document object.

        """
        parts = document_url.split("/")
        if len(parts) % 2 != 0:
            raise ValueError(f"Invalid document URL: {document_url}")

        ref = self.db.collection(parts[0])
        for i in range(1, len(parts)):
            if i % 2 == 0:
                ref = ref.collection(parts[i])
            else:
                ref = ref.document(parts[i])

        doc = ref.get()
        if not doc.exists:
            raise ValueError(f"No such document: {document_url}")
        doc_str = ", ".join([f"{k}: {v}" for k, v in doc.to_dict().items()])
        return Document(text=doc_str)

        Load a single document from Firestore.

        Args:
            document_url (str): The absolute path to the Firestore document to read.

        Returns:
            Document: A Document object.

        
llama-index-integrations/readers/llama-index-readers-firestore/llama_index/readers/firestore/base.py