pub fn withdraw_liquidity(
    deps: DepsMut,
    env: Env,
    info: MessageInfo,
    pool_identifier: String,
) -> Result<Response, ContractError> {
    // --SNIP
    let refund_assets: Vec<Coin> = pool
        .assets
        .iter()
        .map(|pool_asset| {
            Ok(Coin {
                denom: pool_asset.denom.clone(),
                amount: Uint128::try_from(
                    Decimal256::from_ratio(pool_asset.amount, Uint256::one())
                        .checked_mul(share_ratio)?
                        .to_uint_floor(),
                )?,
            })
        })
        .collect::<Result<Vec<Coin>, ContractError>>()?
        .into_iter()
        // filter out assets with zero amount
        .filter(|coin| coin.amount > Uint128::zero())
        .collect();

    let mut messages: Vec<CosmosMsg> = vec![];

    // Transfer the refund assets to the sender
    messages.push(CosmosMsg::Bank(BankMsg::Send {
        to_address: info.sender.to_string(),
        amount: refund_assets.clone(),
    }));

    // --SNIP
}
