Create test with empty or nil string
Create StringCalc0706 class and Calc functions
Green
Refactor
test with string contains 1 number  _ RED
Green
Refactor
Test with string contains 2 numbers - RED
Green
Refactor
Test with string contains more than 2 numbers
Test with string contains new line - RED
Green
Refactor
Test with string to support different delimiters - RED
Green
Refactor
Test with string contains negative number - RED
Green
Refactor