#[constructor]
fn constructor(ref self: ContractState, _owner: ContractAddress)

 #[external(v0)]
 fn swap(ref self: ContractState, route: RouteParam, swap_parameters: Array<SwapParams>)

#[derive(Drop, starknet::Event)]
struct Swap {
    sender: ContractAddress,
    token_in: ContractAddress,
    token_out: ContractAddress,
    amount_in: u256,
    amount_out: u256,
    to: ContractAddress
}