code: protected static function symbol($symbol) {
  		if ($symbol instanceof Symbol)
  			return [$symbol->symbol, $symbol->package];
  	
  		throw new \UnexpectedValueException(sprintf("Unexpected value of type '%s'.", is_object($symbol) ? get_class($symbol) : gettype($symbol)));
  	}
docs: Validates a aymbol
  @param \eMacros\Symbol $symbol
  @throws \UnexpectedValueException
  @return array