LLMGraphTransformer with gemini giving error

[arjun9689]

Below is the code I am trying to execute:

from dotenv import load_dotenv
load_dotenv()
import os

from langchain_google_genai import ChatGoogleGenerativeAI, GoogleGenerativeAIEmbeddings
from langchain_experimental.graph_transformers import LLMGraphTransformer
import google.generativeai as genai

genai.configure(api_key=os.getenv("GOOGLE_API_KEY"))
llm = ChatGoogleGenerativeAI(model="gemini-1.5-pro")

text = """Marie Curie, born in 1867, was a Polish and naturalised-French physicist and chemist who conducted pioneering research on radioactivity.She was the first woman to win a Nobel Prize, the first person to win a Nobel Prize twice, and the only person to win a Nobel Prize in two scientific fields.Her husband, Pierre Curie, was a co-winner of her first Nobel Prize, making them the first-ever married couple to win the Nobel Prize and launching the Curie family legacy of five Nobel Prizes.She was, in 1906, the first woman to become a professor at the University of Paris."""

from langchain_core.documents import Document
documents = [Document(page_content=text)]
llm_transformer = LLMGraphTransformer(llm=llm)
graph_documents = llm_transformer.convert_to_graph_documents(documents)

Below is the error I am getting:

ChatGoogleGenerativeAIError: Invalid argument provided to Gemini: 400 * GenerateContentRequest.tools[0].function_declarations[0].parameters.properties[relationships].items: missing field.
* GenerateContentRequest.tools[0].function_declarations[0].parameters.properties[nodes].items: missing field.

[marfago]

It seems that the Optional[List] is not supported (Gemini is complaining because of a type=null).
Try to remove it as follows:

class DynamicGraph(_Graph):
        """Represents a graph document consisting of nodes and relationships."""

        nodes: List[SimpleNode] = Field(description="List of nodes")  # type: ignore
        relationships: List[SimpleRelationship] = Field(  # type: ignore
            description="List of relationships"
        )

Unfortunately it may cause a failure if the list of nodes/relationships is empty.