protected function getStyleCodes(string $tag): array
	{
		if(isset($this->styles[$tag]))
		{
			return [$this->styles[$tag]];
		}
		elseif(isset($this->userStyles[$tag]))
		{
			$codes = [];

			foreach($this->userStyles[$tag] as $tag)
			{
				$codes = array_merge($codes, $this->getStyleCodes($tag));
			}

			return $codes;
		}

		throw new FormatterException(vsprintf('Undefined formatting tag [ %s ] detected.', [$tag]));
	}