class_docstr: A class for handling connections and interactions with the Plaid API.
  
  Attributes:
      plaid_env (str): Enviroment used by user [ 'sandbox'(default) OR 'development' OR 'production' ].
      client_id (str): Your Plaid API client_id. 
      secret (str): Your Plaid API secret
      access_token (str): The access token for the Plaid account.
docstr: Authenticate with the Plaid API using the API keys and secrets stored in the `plaid_env`, `client_id`, `secret` , and `access_token`  attributes.
docstr_tok: ["Authenticate","with","the","Plaid","API","using","the","API","keys","and","secrets","stored","in","the","`","plaid_env","`",",","`","client_id","`",",","`","secret","`",",","and","`","access_token","`","attributes","."]
code: def connect(self):
      """Authenticate with the Plaid API using the API keys and secrets stored in the `plaid_env`, `client_id`, `secret` , and `access_token`  attributes."""  # noqa
  
      if self.is_connected is True:
          return self.api
  
      api_client = plaid.ApiClient(self.plaid_config)
      self.api = plaid_api.PlaidApi(api_client)
      self.is_connected = True
      return self.api
  
imports: import pandas
  from mindsdb.utilities import log
  from mindsdb_sql import parse_sql
  from mindsdb.integrations.libs.api_handler import APIHandler, FuncParser
  from mindsdb.integrations.libs.response import HandlerStatusResponse, HandlerResponse, RESPONSE_TYPE
  from datetime import datetime
  import plaid
  from plaid.api import plaid_api
  from plaid.model.accounts_balance_get_request import AccountsBalanceGetRequest
  from plaid.model.accounts_balance_get_request_options import AccountsBalanceGetRequestOptions
  from plaid.model.transactions_get_request import TransactionsGetRequest
  from plaid.model.transactions_get_request_options import TransactionsGetRequestOptions
  from .plaid_tables import BalanceTable, TransactionTable
  from .utils import parse_transaction
label_desc: Use image node_id 2 for calling the PlaidHandler obj's underlying member method code with example usage: obj.connect() and returns: self, self