Is there a way to make Typescript smarter when implementing a class?

class AbstractClass {
    testMethod: (a: string, b: number) => Promise<boolean>
    testMethodTwo: (a: string, b: number) => Promise<boolean>
}

class TSClass implements AbstractClass {
    async testMethod(a, b) { // no intellisense

        return true
    }
    async testMethodTwo(a: string, b: number) {

        return true
    }
}

class AbstractClass {
    testMethod: (a: string, b: number) => Promise<boolean>
    testMethodTwo: (a: string, b: number) => Promise<boolean>
}

class TSClass implements AbstractClass {
    async testMethod(a, b) { // no intellisense

        return true
    }
    async testMethodTwo(a: string, b: number) {

        return true
    }
}