Payment/Model/PaymentSubjectTrait.php
public function isPaid()
    {
        // TRUE If paid total is greater than or equals grand total
        return 0 <= Money::compare($this->paidTotal, $this->grandTotal, $this->getCurrency()->getCode());
    }
public function isPaid()
    {
        // TRUE If paid total is greater than or equals grand total
        return 0 <= Money::compare($this->paidTotal, $this->grandTotal, $this->getCurrency()->getCode());
    }
Returns whether or not the subject is fully paid.

@return bool