Implement a demo using observer pattern to simulate teacher and student communication platform. When a teacher post a message, every student registered with this teacher should receive the corresponding message. This platform can check the most updated messages from all teachers from a particular student under request. This implementation is a simple simulation of the teacher/student communication platform. You are required to at least demonstrate the basic communication shown in the sample run. 10 bonus points will be given to student who has a more flexible communication demonstration. Sample run: Please input the student name to check all his or her message! Alex Current Message from Current Message from Tom We have a test tomorrow! Barry Class canceled tomorrow! Do you want to continue (Yes/No)? yes Please input the student name to check all his or her message! Alpha Current Message from Tom We have a test tomorrow! Do you want to continue (Yes/No)?