INVALID_CONCURRENT_GRAPH_UPDATE

class State(TypedDict):
    some_key: str

def node(state: State):
    return {"some_key": "some_string_value"}

def other_node(state: State):
    return {"some_key": "some_string_value"}


builder = StateGraph(State)
builder.add_node(node)
builder.add_node(other_node)
builder.add_edge(START, "node")
builder.add_edge(START, "other_node")
graph = builder.compile()

import operator
from typing import Annotated

class State(TypedDict):
    # The operator.add reducer fn makes this append-only  #
    some_key: Annotated[list, operator.add]