/// <summary>
 /// Compared the value of the <see cref="Mileage"/> property with that of another <see cref="Location"/> instance.
 /// </summary>
 /// <param name="other">A <see cref="Location"/> object to compare.</param>
 /// <returns>An integer indicating whether the <see cref="Mileage"/> property of this object is less than, equal to or greater than that of the parameter.</returns>
 public int CompareTo(Location other)
 {
     if (other is null || other.Mileage == null)
     {
         return(Mileage == null ? 0 : 1);
     }
     if (Mileage == null)
     {
         return(-1);
     }
     return(Mileage.CompareTo(other.Mileage));
 }
 /// <summary>
 /// Compares the value of the <see cref="Mileage"/> property with a <see cref="Distance"/> parameter.
 /// </summary>
 /// <param name="other">A <see cref="Distance"/> parameter to compare.</param>
 /// <returns>An integer indicating whether the <see cref="Mileage"/> property is less than, equal to or greater than the parameter.</returns>
 public int CompareTo(Distance other)
 {
     if (other is null)
     {
         return(Mileage == null ? 0 : 1);
     }
     if (Mileage == null)
     {
         return(-1);
     }
     return(Mileage.CompareTo(other));
 }