code: @Override
      public String getUsernameFromQuery(final Map<String, List<Object>> query) {
          final List<Object> usernameAttributeValues = query.get(this.usernameAttribute);
  
          if (usernameAttributeValues == null || usernameAttributeValues.size() == 0) {
              return null;
          }
  
          final Object firstValue = usernameAttributeValues.get(0);
          if (firstValue == null) {
              return null;
          }
  
          final String username = StringUtils.trimToNull(String.valueOf(firstValue));
          if (username == null || username.contains(IPersonAttributeDao.WILDCARD)) {
              return null;
          }
  
          return username;
      }
docs: /* (non-Javadoc)
  @see org.jasig.services.persondir.support.IUsernameAttributeProvider#getUsernameFromQuery(java.util.Map)