class_docstr: Tests the /upload_file endpoint.
class_docstr_tok: ["Tests","the","\/upload_file","endpoint","."]
docstr: Uploading multiple files will error
docstr_tok: ["Uploading","multiple","files","will","error"]
code: def test_upload_multiple_files_error(self):
      """Uploading multiple files will error"""
      file_1 = MockFile("file1", b"123")
      file_2 = MockFile("file2", b"456")
  
      files_body = {
          file_1.name: file_1.data,
          file_2.name: file_2.data,
      }
      response = self._upload_files(
          files_body,
          session_id="some-session-id",
          file_id="some-file-id",
      )
      self.assertEqual(400, response.code)
      self.assertIn("Expected 1 file, but got 2", response.reason)
  
imports: from typing import NamedTuple
  import requests
  import tornado.testing
  import tornado.web
  import tornado.websocket
  from streamlit.logger import get_logger
  from streamlit.runtime.memory_uploaded_file_manager import MemoryUploadedFileManager
  from streamlit.runtime.uploaded_file_manager import UploadedFileManager
  from streamlit.web.server.server import UPLOAD_FILE_ENDPOINT
  from streamlit.web.server.upload_file_request_handler import UploadFileRequestHandler
label_desc: Use image node_id 4 for calling the UploadFileRequestHandlerTest obj's underlying member method code with example usage: obj.test_upload_multiple_files_error() without return types