code: public boolean isFiltered(String filterExpression) {
          if(_filters == null || filterExpression == null)
              return false;
  
          ArrayList list = lookupFilters(filterExpression);
          if(list != null && list.size() > 0)
              return true;
          else return false;
      }
docs: Utility method that checks to see if the given <code>filterExpression</code> matches any of the current
  {@link Filter} instances.
  @param filterExpression the filter expression to check
  @return <code>true</code> if at least one filter matches the <code>filterExpression</code>; <code>false</code>
  otherwise.