stringContainsInOrder method
Returns a matcher that matches if the match argument is a string and
contains a given list of substrings
in relative order.
For example, stringContainsInOrder(["a", "e", "i", "o", "u"])
will match
"abcdefghijklmnopqrstuvwxyz".
Implementation
Return stringContainsInOrder(List<String> substrings) {
return runMatcher(dart_test.stringContainsInOrder(substrings));
}