This is a test Project with a Java Main test program. It's documented at:

https://collatz-explorers-club.atlassian.net/wiki/spaces/CECMS/pages/819202/Creating+Git+Repository+And+Adding+And+Checking+Out+Projects+In+Eclipse

and you should be able to check it out by following instructions at:

https://collatz-explorers-club.atlassian.net/wiki/spaces/CECMS/pages/819202/Creating+Git+Repository+And+Adding+And+Checking+Out+Projects+In+Eclipse#Testing-Checking-Out-Project-Into-Different-Workspace

which tells you how clone this Project repo into Eclipse, import as a Maven project and run the test program.