code: def get_columns(self, table_name: str) -> DBHandlerResponse:
      columns = [
          "ts",
          "text",
          "message_created_at",
          "user",
          "channel",
          "reactions",
          "attachments",
          "thread_ts",
          "reply_count",
          "reply_users_count",
          "latest_reply",
          "subtype",
          "hidden",
      ]
      columns_df = pd.DataFrame(columns, columns=["column_name"])
      return DBHandlerResponse(data=columns_df)
  
file_path: evadb/evadb/third_party/databases/slack/slack_handler.py
imports: import pandas
  from slack_sdk import WebClient
  from slack_sdk.errors import SlackApiError
  from evadb.third_party.types import DBHandler, DBHandlerResponse, DBHandlerStatus
label_desc: Use image node_id 6 for calling the SlackHandler obj's underlying member method code with example usage: obj.get_columns(table_name) and returns: DBHandlerResponse