When the mapper needs to map a source to a union of objects, it will try
to guess which object it will map to, based on the needed arguments of
the objects, and the values contained in the source.
```php
final class UnionOfObjects
{
public readonly SomeFooObject|SomeBarObject $object;
}
final class SomeFooObject
{
public readonly string $foo;
}
final class SomeBarObject
{
public readonly string $bar;
}
// Will map to an instance of `SomeFooObject`
(new \CuyZ\Valinor\MapperBuilder())
->mapper()
->map(UnionOfObjects::class, ['foo' => 'foo']);
// Will map to an instance of `SomeBarObject`
(new \CuyZ\Valinor\MapperBuilder())
->mapper()
->map(UnionOfObjects::class, ['bar' => 'bar']);
```
