src/Builders/RouteBuilder.php
public function withAttribute(string $name, $value): self
    {
        $this->attributes[$name] = $value;

        return $this;
    }
public function withAttribute(string $name, $value): self
    {
        $this->attributes[$name] = $value;

        return $this;
    }
Binds a custom attribute to the route
This is useful for custom route constraint matching

@param string $name The name of the attribute
@param mixed $value The value of the attribute
@return self For chaining