isIn method
Checks if the String
exists in a given Iterable<String>
Example
String foo = '6d64-4396-8547-1ec1b86e081e';
var iterable = ['fff','gasd'];
bool isIn = foo.isIn(iterable); // returns false
Implementation
bool isIn(Iterable<String> strings) => isNotBlank && strings.isNotEmpty && strings.contains(this);