function _executeArbitraryCalls(
        IProposalExecutionEngine.ExecuteProposalParams memory params
    )
        internal
        returns (bytes memory nextProgressData)
    {

...
uint256 ethAvailable = msg.value;
        for (uint256 i = 0; i < calls.length; ++i) {
            // Execute an arbitrary call.
            _executeSingleArbitraryCall(
                i,
                calls[i],
                params.preciousTokens,
                params.preciousTokenIds,
                isUnanimous,
                ethAvailable
            );
            // Update the amount of ETH available for the subsequent calls.
            ethAvailable -= calls[i].value;
            emit ArbitraryCallExecuted(params.proposalId, i, calls.length);
        }
....
}
