Legal analysis: A witness refers to a person who proves that the loan contract relationship does exist, and does not need to bear joint liability. Therefore, the witness signing his or her name proves the fact that the contractual relationship exists. Generally, the guarantor has a preemptive defense right, that is, the guarantor can refuse to assume guarantee liability to the creditor before the main contract dispute has not been tried or arbitrated, and the debtor's property has been legally enforced and the debt cannot be fulfilled.

Legal basis: Article 694 of the "People's Republic of China and Civil Code" If a creditor of a general guarantee files a lawsuit or applies for arbitration against the debtor before the expiration of the guarantee period, the guarantor shall refuse to assume the guarantee. The statute of limitations for guaranteed debts begins to run from the date when the right to liability is extinguished.