return null;
}
Matcher customComparatorMatcher = customComparatorPattern.matcher(expression);
if (customComparatorMatcher.matches()) {
String prefix = customComparatorMatcher.group(1);
CustomComparator customComparator = customComparatorRegistry.getCustomComparatorForPrefix(prefix);
if (customComparator != null) {
String expectedString = customComparatorMatcher.group(2);
try {
if (customComparator.matches(actual, expectedString)) {
message = SlimTestResult.pass(expectedString + " matches " + actual);
} else {
message = SlimTestResult.fail(expectedString + " doesn't match " + actual);
}
} catch (Throwable t) {