Whether or not a claim is in dispute does not make it an unliquidated claim. If the amount of the claim in question can not be determined within a specified time frame the bankruptcy court will allow the amount of the claim to be estimated to ensure the creditor will have certain rights to share the value of the debtor's assets.
There are not codified laws in the bankruptcy code to precisely estimate the value of an unliquidated claim. The bankruptcy court can use their discretion to evaluate the case and make decisions based on the needs of the individual bankruptcy proceeding. Estimation proceedings can be a simple bankruptcy proceeding without testimony.