class_docstr: A class for handling connections and interactions with the CoinBase API.
  
  Attributes:
      api_key (str): API key
      api_secret (str): API secret
      is_connected (bool): Whether or not the API client is connected to CoinBase.
docstr: Creates a new CoinBase API client if needed and sets it as the client to use for requests.
  
  Returns newly created CoinBase API client, or current client if already set.
docstr_tok: ["Creates","a","new","CoinBase","API","client","if","needed","and","sets","it","as","the","client","to","use","for","requests",".","Returns","newly","created","CoinBase","API","client",",","or","current","client","if","already","set","."]
code: def connect(self):
      """Creates a new CoinBase API client if needed and sets it as the client to use for requests.
  
      Returns newly created CoinBase API client, or current client if already set.
      """
      self.is_connected = True
      return self.client
  
imports: import pandas
  from typing import Dict
  import datetime
  import hmac
  import hashlib
  import time
  import requests
  from collections import OrderedDict
  import base64
  from mindsdb.integrations.handlers.coinbase_handler.coinbase_tables import CoinBaseAggregatedTradesTable
  from mindsdb.integrations.libs.api_handler import APIHandler
  from mindsdb.integrations.libs.const import HANDLER_CONNECTION_ARG_TYPE
  from mindsdb.integrations.libs.response import HandlerStatusResponse, HandlerResponse
  from mindsdb_sql import parse_sql
label_desc: Use image node_id 2 for calling the CoinBaseHandler obj's underlying member method code with example usage: obj.connect() and returns: self