public function addTag($key, $value)
{
$key = trim($key);
if ($key === '') {
throw new Exception('Tag Key must not be empty', 1448264366);
}
$value = trim($value);
if ($value === '') {
throw new Exception('Tag Value must not be empty', 1448264367);
}
$tag = Functions::ucfirst($key) . 'DynamicTag_' . $value;
$this->tags[$tag] = true;
}