Use the Observer pattern to design and implement a Grass-cutting Machine Monitoring System based on the following instructions: The monitoring system should be implemented with three different types of Monitors (simple, medium, advanced). The monitoring system can notify five different levels of current state of a grass-cutting machine listed below: WORKING-NORMALLY MINOR-REPAIR-NEEDED MAJOR-REPAIR-NEEDED HARD-TO-FIX TOTALLY-BROKEN The simple monitor can only listen to one machine and notify whether or not the machine needs repair; the medium monitor can listen to two different machines, notify whether repair is needed and also indicate the level of the repair for each machine; the advanced monitor can listen to up to five different machines, notify whether repair is needed and also indicate the level of the repair for each machine. All the outputs generated by your program MUST be written into an output file named "output_LastName.txt", where LastName is your Last Name. You have the freedom to decide what outputs should be written to this output file. How and What to submit for this assignment? You must use the NetBeans feature "Export Project to Zip" to zip your project for the assignment. Submit the following three items to CougarView: (30%) the ZIP file containing all the Java source files (20%) the file "output_lastName.txt" that contains all the outputs of your program (50%) the UML class diagram in a PDF or PNG file. Note:- please give UML class diagram using voiletuml editor