Function: claim(uint256 epoch)
This function claims collateral from the vault.
Inputs
epoch
Control: Completely controlled by the caller.
Constraints: Must be less than the current epoch.
Impact: Epoch to claim the collateral for.
Branches and code coverage (including function calls)
Intended branches
Amount withdrawn in the previous epoch is transferred to the caller.
Negative behavior
Reverts if called with the current or future epoch.
Reverts if called twice in the same epoch.
Reverts if withdrawable amount is zero.