$attributes Additional attributes */ public function __construct(Expr $left, Expr $right, array $attributes = []) { $this->attributes = $attributes; $this->left = $left; $this->right = $right; } public function getSubNodeNames(): array { return ['left', 'right']; } /** * Get the operator sigil for this binary operation. * * In the case there are multiple possible sigils for an operator, this method does not * necessarily return the one used in the parsed code. */ abstract public function getOperatorSigil(): string; }