public function testToReadableString()
{
$ma0 = new MutableArray([]);
$this->assertEquals('', $ma0->toReadableString(', ', ' and '));
$ma1 = new MutableArray(['a']);
$this->assertEquals('a', $ma1->toReadableString(', ', ' and '));
$ma2 = new MutableArray(['a', 'b']);
$this->assertEquals('a and b', $ma2->toReadableString(', ', ' and '));
$ma3 = new MutableArray(['a', 'b', 'c']);
$this->assertEquals('a + b and c', $ma3->toReadableString(' + ', ' and '));
$ma4 = new MutableArray(['a', 'b', 'c', 'd']);
$this->assertEquals('a, b, c or d', $ma4->toReadableString(', ', ' or '));
}
