Binary1.php

<?php

class Node
{
    private $value;
    private $left;
    private $right;

    public function __construct(string $value, ?Node $left, ?Node $right)
    {
        $this->left = $left;
        $this->right = $right;
        $this->value = $value;
    }

    public function getValue(): string
    {
        return $this->value;
    }

    public function getLeft(): ?Node
    {
        return $this->left;
    }

    public function getRight(): ?Node
    {
        return $this->right;
    }
}