public function normalize( $rule ) {
		$rule = ucwords( str_replace( [ '-', '_' ], ' ', $rule ) );
		$rule = lcfirst( str_replace( ' ', '', $rule ) );

		switch ( $rule ) {
			case 'creditcard':
				return 'creditCard';
			case 'int':
				return 'integer';
			case 'bool':
				return 'boolean';
			default:
				return $rule;
		}
	}