IITK at SemEval-2021 Task 10: Source-Free Unsupervised Domain Adaptation using Class Prototypes. - Harshit Kumar; Jinang Shah; Nidhi Hegde 002; Priyanshu Gupta; Vaibhav Jindal; Ashutosh Modi (SemEval@ACL/IJCNLP, 2021)