/// <summary>
/// Finds first book with equal value of specified parameter
/// </summary>
/// <param name="predicate">Predicate which specifies tag by value of which book will be chosen</param>
/// <param name="value">Value by which book will be chosen</param>
/// <returns></returns>
public Book FindBook <T>(IPredicate <T> predicate, T value)
{
if (predicate == null)
{
throw new ArgumentNullException();
}
foreach (var book in Books)
{
if (predicate.FitsTheTag(book, value))
{
return(book);
}
}
return(null);
}