386: function collect(uint256 userId, IERC20 erc20)
387:     public
388:     whenNotPaused
389:     onlyDriver(userId)
390:     returns (uint128 amt)
391: {
392:     amt = Splits._collect(userId, _assetId(erc20));
393:     _decreaseTotalBalance(erc20, amt);
394:     erc20.safeTransfer(msg.sender, amt);
395: }
