Create swap_small method to find the smallest value in an array and swap it with the first method in an array. Make failing tests pass.
Create sum_2 method to determine if any 2 elements within an array add up to zero. Make failing tests pass. Return true if it includes zeros or the positive and negative values of the same number. Return false if empty or other.
Updatefind_sum_3 method to make all tests pass. Accounts for an empty array, and array that includes a 0, and any arrays with any negative values. Otherwise assumes false.
Update sum_arrays method to use the each_index method instead of the while loop as a preferable solution.
Refactor swap_small method to use the each_index method instead of a while loop as a preferrable solution.
Refactor to reduce the swap portion of the method to require fewer steps using a direct replacement rather than insert/delete and shift/unshift.
Updated to include optimal solutions for the sum_2 and sum_3 methods.