The Extensions.sol contract handles the logic necessary to request and vote on extensions. During the course of a loan, the borrower has the opportunity to for a single extension of the instalment deadline. Lenders in favour of the extension are required to vote in support for it, wherein their voting power is proportional to their balance of the pool tokens. While only one extension can be granted, the borrower can place a request multiple times during the loan period (of course, once an extension has been granted, further requests are rejected automatically).