Roman numerals Kata

RomanNumerals.php

<?php

namespace App;

class RomanNumerals
{
    const NUMERALS = [
        'M' => 1000,
        'CM' => 900,
        'D' => 500,
        'CD' => 400,
        'C' => 100,
        'XC' => 90,
        'L' => 50,
        'XL' => 40,
        'X' => 10,
        'IX' => 9,
        'V' => 5,
        'IV' => 4,
        'I' => 1
    ];

    public static function generate(int $number)
    {
        if ($number <= 0 || $number >= 4000) {
            return false;
        }

        $result = '';

        foreach (static::NUMERALS as $numeral => $arabic) {
            for (; $number >= $arabic; $number -= $arabic) {
                $result .= $numeral;
            }
        }

        return $result;
    }
}

RomanNumeralsTest.php

<?php

use App\RomanNumerals;
use PHPUnit\Framework\TestCase;

class RomanNumeralsTest extends TestCase
{
    /**
     * @test
     * @dataProvider checks
     */
    function it_generates_roman_numerals($number, $numeral)
    {
        $this->assertEquals($numeral, RomanNumerals::generate($number));
    }

    /** @test */
    function it_cannot_generate_a_roman_numeral_for_less_than_1()
    {
        $this->assertFalse(RomanNumerals::generate(0));
    }

    /** @test */
    function it_cannot_generate_a_roman_numeral_for_more_than_3999()
    {
        $this->assertFalse(RomanNumerals::generate(4000));
    }

    public function checks()
    {
        return [
            [1, 'I'],
            [2, 'II'],
            [3, 'III'],
            [4, 'IV'],
            [5, 'V'],
            [6, 'VI'],
            [7, 'VII'],
            [8, 'VIII'],
            [9, 'IX'],
            [10, 'X'],
            [40, 'XL'],
            [50, 'L'],
            [90, 'XC'],
            [100, 'C'],
            [400, 'CD'],
            [500, 'D'],
            [900, 'CM'],
            [1000, 'M'],
            [3999, 'MMMCMXCIX']
        ];
    }
}

I think it defeats the purpose of the Kata, but saw this elegant solution on exercism.org :)

<?php

function toRoman(int $number): string
{
    // Cf. https://www.php.net/manual/de/class.numberformatter.php
    // and https://github.com/unicode-org/icu/blob/master/icu4c/source/data/misc/numberingSystems.txt

    return (new NumberFormatter('@numbers=roman', NumberFormatter::DECIMAL))
        ->format($number);
}