code: def api_append_block():
      data = request.get_json()
      session.api_append_block(data)
      return json.dumps({"result": "ok"}) + "\n"
  
imports: import sys
  import os
  from model import ExLlama, ExLlamaConfig
  from flask import Flask, render_template, request, jsonify
  from flask import Response, stream_with_context
  from threading import Timer, Lock
  import webbrowser
  import json
  import model_init
  from session import prepare_sessions, get_initial_session, Session, load_session, new_session, _sessions_dir
  import argparse
  from tokenizer import ExLlamaTokenizer
  from waitress import serve
label_desc: Use image node_id 12 for calling a global function with example usage: api_append_block() and returns: unknown