Beeson Company made a contract to construct a shopping center for Sartori. Before the work was fully completed, Sartori stopped making the payments to Beeson that the contract required. The contract provided for liquidated damages of $1,000 per day if Beeson failed to substantially complete the project within 300 days of the beginning of construction. The contract also provided for a bonus of $1,000 for each day Beeson completed the project ahead of schedule. Beeson stopped working and sued Sartori for the balance due under the contract, just as though it had been fully performed. Sartori defended on the ground that Beeson had not substantially completed the work. Beeson proved that Sartori had been able to rent most of the stores in the center. Was there substantial performance of the contract? If so, what would be the measure of damages?