@Override
    public boolean matches(Object o) {
        String s = (String)o;
        String[] lines = s.split("\n");
        for (String line : lines)
            if (line.matches(pattern))
                return true;
        return false;
    }
Checks if a multi-line string contains at least one line with the expected regex pattern.

@author gjoranv
@since 5.1.7
testutil/src/main/java/com/yahoo/test/LinePatternMatcher.java