/// <summary>
/// Adds a single currency <see cref="Balance"/> to the current <see cref="CompositeBalance"/> and returns the new composite balance.
/// </summary>
/// <param name="balance">The balance to combine with the current composite balance.</param>
/// <returns>The new composite balance.</returns>
public CompositeBalance CombineWith(Balance balance)
{
return this.CombineWith(balance.Security, balance.Amount, balance.IsExact);
}