pub fn add_receiver_api_callback<S: ReadonlyStorage>(
    storage: &S,
    messages: &mut Vec<CosmosMsg>,
    recipient: HumanAddr,
    recipient_code_hash: Option<String>,
    msg: Option<Binary>,
    sender: HumanAddr,
    from: HumanAddr,
    amount: Uint128,
    memo: Option<String>
) -> StdResult<()>