Inversify Issue resolving Concreate Implementation

import { ITransfer } from '../Interfaces/itransfer'
import { injectable } from "inversify";
import "reflect-metadata"

export interface ITransfer {
    amount: number
    global_index:number
    toHMSET():string[]
}

@injectable()
export class ConreteTransfer implements ITransfer {

    private amount:number
    private global_index:number
    public toHMSET() : string[] {
        return ['hmset', `transfer:${this.global_index}`, 'amount', `${this.amount}`]
    }
}

export const containerModules = new ContainerModule((bind) => {
    bind<ITransfer>(TYPES.Transfer).to(ConcreteTransfer)
})


@injectable()
export class example {
public RecordIncomingTransfers(transfers:Array<ITransfer>) : void {
            let commands:string[][] = new Array<Array<string>>()
            for (var i = transfers.length - 1; i >= 0; i--) {
                commands.push(transfers[i].toHMSET())   //TypeError: transfers[i].toHMSET is not a function
            }
            console.log(commands)
    }
}