);
		preg_match( $first_tag, $content, $matches );

		// If there is a tag, but it doesn't have a class attribute, add the class attribute.
		if ( isset( $matches[0] ) && strpos( $matches[0], ' class=' ) === false ) {
			$pattern_before_tag_closing = '/.+?(?=>)/';
			return preg_replace( $pattern_before_tag_closing, '$0 class="' . $align_class_and_style['class'] . '"', $content, 1 );
		}

		// If there is a tag, and it has a class already, add the class attribute.
		$pattern_get_class = '/(?<=class=\"|\')[^"|\']+(?=\"|\')/';
		return preg_replace( $pattern_get_class, '$0 ' . $align_class_and_style['class'], $content, 1 );
	}
}