Define a class named Document that contains a member variable of type string named text that stores any textual content for the document. Create a function getText() that returns the text field and a way to set this value. Next, define a class for Email that is derived from Document and that includes member variables for the sender and recipient. Implement appropriate accessor and mutator functions. The body of the email message should be stored in the inherited variable text. Test both classes in main. Make sure you have appropriate constructors.