The workers at Nikas Nail & Beauty Bar, Dan and Sam, have been pestering Nika for weeks about getting an increase in their hourly rate. Nika repeatedly explains to Dan and Sam that she cannot agree to a pay rise without first speaking to her accountant, and that she will not have time to do so until the end of the month. Dan and Sam are becoming increasingly frustrated with Nikas refusal to consider their request. One Friday evening, during the busiest part of the shift, Dan and Sam confront Nika and tell her that unless she agrees to increase their hourly rate by $5 per hour, they are going to walk out, leaving her to serve the customers on her own. Nika has no choice but to agree to their request. She promises to adjust their pay as requested.

Is Nika legally obliged to keep her promise? Focus upon whether or not Dan and Sam have engaged in duress. You must use relevant cases to support your answer.