SearchParams Refactored

SearchParams.php

<?php
final class SearchParams {
    private $username;
    private $name;
    private function __construct(string $username, string $name) {
        $this->username = $username;
        $this->name = $name;
    }
    public static function fromArray(array $params) : SearchParams {
        if (empty($params["username"])) {
            throw new \Exception("Username is required.");
        }
        if (empty($params["name"])) {
          $first = $params["first_name"] ?? '';
          $last = $params["last_name"] ?? '';
          $params["name"] = "$first $last";
        }
        
        return new static($params["username"], $params["name"]);
    }
    public function toArray() : array {
        return [
            "username" => $this->username,
            "name" => $this->name
        ];
    }
}