src/Tokenizer/Token.php
public function isWhitespace($whitespaces = " \t\n\r\0\x0B")
    {
        if (null === $whitespaces) {
            $whitespaces = " \t\n\r\0\x0B";
        }

        if ($this->isArray && !$this->isGivenKind(T_WHITESPACE)) {
            return false;
        }

        return '' === trim($this->content, $whitespaces);
    }
public function isWhitespace($whitespaces = " \t\n\r\0\x0B")
    {
        if (null === $whitespaces) {
            $whitespaces = " \t\n\r\0\x0B";
        }

        if ($this->isArray && !$this->isGivenKind(T_WHITESPACE)) {
            return false;
        }

        return '' === trim($this->content, $whitespaces);
    }
Check if token is whitespace.

@param null|string $whitespaces whitespace characters, default is " \t\n\r\0\x0B"

@return bool