first test for empty string - fail
fixed the failure by returning 0 - passed
add test for one number given - fail
fix failure for one number - passed
refactoring - for easy use in each test , make initialize function
before each test
test after refactoring
test two numbers separated with comma - failed
fix failure for 2 numbers - passed
refactoring method for Integer.parseInt
test after refactor - passed
add test for two numbers with new line between them - fail
fix that will work with new line - passed
test refactoring method that returns the sum of two numbers - passed
add test for negative numbers - fail
fix negative numbers test - passed
refactoring and test refactor - passed