Should every possible branch in a method have a separate junit?
if (x == 5) {
  c = 1;
} else {
 if (z != 2) {
  b = 6;
} else {
   a = 3;
}

void testMethod() {
// x is 5
test/assert code;

// x not 5, z not 2
test/assert code;

// x not 5, z is 2
test/assert code

// etc
}