protected Matcher getUserNameMatcher(String requestUri) {
    return USER_NAME_IN_URI_REGEXP.matcher(requestUri);
  }
Returns a {@link Matcher} created from {@link #USER_NAME_IN_URI_REGEXP} for the
provided requestUri.
@param requestUri the Uri the Matcher is created for.
@return the matcher
ambari-server/src/main/java/org/apache/ambari/server/api/UserNameOverrideFilter.java