protected function _quoteValue($value)
    {
        if(is_numeric($value)) {
            return false;
        }

        if(strpos($value, $this->separator) !== false) { // Separator is present in field
            return true;
        }

        if(strpos($value, $this->quote) !== false) { // Quote character is present in field
            return true;
        }

        if (strpos($value, "\n") !== false || strpos($value, "\r") !== false ) { // Newline is present in field
            return true;
        }

        if(substr($value, 0, 1) == " " || substr($value, -1) == " ") {  // Space found at beginning or end of field value
            return true;
        }

        return false;
    }