$tron->contract() throws exception

[ershad7]

When trying to interact with TRC20 USDT contract the following code:

$tron->contract('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t');

throws and exception "Failed to execute. Error:Smart contract is not exist."

most of the other issues are due to this function not working.