The superclass Student contains:
a constructor that accepts a String corresponding to the name of the school the student attends
a toString method that returns 'student at X' where X is the name of the school the student attends.
write a class definitions for the subclass HighSchoolStudent containing:
a constructor accepting a String which is used as a parameter to the superclass constructor
a toString method that returns 'high school student at X'. THis method must use the toString method of its superclass.