Write a method that concatenates two strings 'str1' and 'str2' but only include the overlap between the end of 'str1' and the start of 'str2' ONCE. For example, if 'str1' is "abcDEF" and 'str2' is "DEF234", the "DEF" is the overlap of the two strings. The idea is that the two strings can be combined into one string without repeating the overlap. So, the result would be "abcDEF234". You are not eliminating the overlap. You are just including it once. Look at the test data for additional examples. This problem is slightly more difficult that it first appears! Note: If there is NO overlap between the two strings, you simply concatenate the two strings.