Look at the following code for the Book class:Public Class Book' Private member variab...

Look at the following code for the Book class:

Public Class Book' Private member variablesPrivate strTitle As StringPrivate strAuthor As StringPrivate strPublisher As StringPrivate strlsbn As String' ConstructorPublic Sub New()strTitle = String.Empty strAuthor = String.EmptystrPublisher = String.Emptystrlsbn = String.Empty End Sub' Title PropertyPublic Property Title() As String GetReturn strTitleEnd GetSet(ByVal value As String) strTitle = valueEnd SetEnd Property' Author propertyPublic Property Author() As StringGetReturn strAuthorEnd GetSet(ByVal value As String)strAuthor = valueEnd SetEnd Property' Publisher propertyPublic Property Publisher() As String GetReturn strPublisherEnd GetSet(ByVal value As String)strPublisher = valueEnd SetEnd Property' Isbn propertyPublic Property Isbn() As String GetReturn strlsbn End GetSet(ByVal value As String)strlsbn = valueEnd SetEnd PropertyEnd Class

Design a class named TextBook that is derived from the Book class. The TextBookclass should have the following properties:

• Course (string). This property holds the name of the course that the textbook is used for.

• OrderQuantity (integer). This property holds the number of books to order for the course.

The OrderQuantity property cannot be negative, so provide error checking in the property procedure.