Error in type guesser

[Yavin]

Where is an error in guesser, when object is not doctrine entity

Error: Call to a member function hasAssociation() on a non-object"
at vendor/yavin/symfony-form-tree/src/Yavin/Symfony/Form/Type/TreeTypeGuesser.php line 68

[mablae]

See https://github.com/Yavin/symfony-form-tree/blob/master/src/TreeTypeGuesser.php#L68

[franciscomemoli]

Same issue, the problem in my case is that my entity isn't an Doctrine entity, I'm using a data transfer object how is a simple class. So the parent::getMetadata($class); didn't work in my case.
No workaround for the moment. :(