Stack Overflow when district size set to 0 in StarGenerator's generate method.

[rjbeer]

Describe the bug When a district size of zero is used to generate patterns in StarGenerator.java's generate() method, the compiled program causes a stack overflow.

To Reproduce Steps to reproduce the behavior:

1. Use StarGenerator.generate(0) to instantiate an ArrayList<ArrayList\> object
2. Compile program
3. Run program

Expected behavior Should return an empty ArrayList<ArrayList\> object

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: N/A
• Browser: N/A
• Version: Redistricting_1.0.1

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Having looked into the issue a potential solution is to check for this particular case at the beginning of the generate method and if district size == 0 return an empty ArrayList<ArrayList\>

[rjbeer]

@jody Can you assign this to me?

[jody]

I've done the triage, assigned you to the issue, and moved in from To Do to In Progress