Calculator with Method Chaining

export class Calculator {
  private value: number;
  constructor(value: number) {
    this.value = value;
  }
 
  add(value: number): Calculator {
    this.value += value;
    return this;
  }
 
  subtract(value: number): Calculator {
    this.value -= value;
    return this;
  }
 
  multiply(value: number): Calculator {
    this.value *= value;
    return this;
  }
 
  divide(value: number): Calculator {
    if (value === 0) {
      throw 'Division by zero is not allowed';
    }
    this.value /= value;
    return this;
  }
 
  power(value: number): Calculator {
    this.value **= value;
    return this;
  }
 
  getResult(): number {
    return this.value;
  }
}