defuse_nep245/receiver.rs
use near_sdk::{AccountId, PromiseOrValue, ext_contract, json_types::U128};
use super::TokenId;
#[ext_contract(ext_mt_receiver)]
pub trait MultiTokenReceiver {
fn mt_on_transfer(
&mut self,
sender_id: AccountId,
previous_owner_ids: Vec<AccountId>,
token_ids: Vec<TokenId>,
amounts: Vec<U128>,
msg: String,
) -> PromiseOrValue<Vec<U128>>;
}