LooseCoupling.cs

class MainCaller
{
    private IValidator _validator;
    
    public MainCaller(IValidator validator)
    {
        _validator = validator;
    }
    
    public int ValidateAndMultiply(int multiplier)
    {
        int result = validator.Validate();
        return result * multiplier;
    }
}

StrongCoupling.cs

class MainCaller
{
    public int ValidateAndMultiply(int param1, string param2, int multiplier)
    {
        ValidatorClass validator = new ValidatorClass(param1, param2);
        int result = validator.Validate();
        return result * multiplier;
    }
}