anchor.diff:  <3> Also creates an empty `Void[]`
   <4> This triggers a runtime error, but not a compile error. The compiler has very little knowledge of how libraries work and doesn't pick this up as an issue.
   
  +=== null reference
   
  +This code
  +[source, Java]
  +----
  +Thread t = null; 
  +t.yield();
  +----
  +is the same as
  +[source, Java]
  +----
  +Thread t = null; 
  +Thread.yield(); // the method is static
  +----
   
  +So the answer is 4 as it just pauses briefly.
  
positive.code: 
  See the answer at the end.
  
  == Answers
  
  === void arrays
  
negative.code: = Java Puzzles
  Peter Lawrey
  :published_at: 2019-01-31
  
  Here are some odd quiz questions in Java which might have interesting answers.
  
  == Questions
  
  