Challenge: Text Cache

Implement the string_cache() function that returns the inner() function that takes the string value and adds it to the enclosed text.

1. Create the text variable with the value "" (empty string) in the string_cache() function.
2. The inner() function should take the string argument with the default value "".
3. Make the text non-local variable changeable inside the inner() function.
4. If the string argument is not an empty string, add this string to the text non-local variable. After the first string addition, the addition should be with space.
5. The inner() function should return the text enclosed variable.
6. The string_cache() should return the inner() function without calling.
7. Call the string_cache() function and assign the result to the text_cache variable.