Assume that the classes listed in the Java Quick Reference have been imported where appropriate.
Unless otherwise noted in the question, assume that parameters in method calls are not null and that methods are called only when their preconditions are satisfied.
In writing solutions for each question, you may use any of the accessible methods that are listed in classes defined in that question. Writing significant amounts of code that can be replaced by a call to one of these methods will not receive full credit.

This question involves the implementation of the PasswordGenerator class, which generates strings containing initial passwords for online accounts. The PasswordGenerator class supports the following functions.

Creating a password consisting of a specified prefix, a period, and a randomly generated numeric portion of specified length
Creating a password consisting of the default prefix "A", a period, and a randomly generated numeric portion of specified length
Reporting how many passwords have been generated
The following table contains a sample code execution sequence and the corresponding results.
The same value is returned by pwCount for all objects of the PasswordGenerator class.
Write the complete PasswordGenerator class. Your implementation must meet all specifications and conform to the example.