[Bug] Error while trying to serialize stix object

[scripton8]

Expected Behavior

Printing stix data using normal print command, also tried with MitreAttackData.print_stix_object() function

Actual Behavior

I receive the following error: serialize() should be provided by the STIX2 base class.

Steps to Reproduce the Problem

1. Get a stix object (in my case with mitre_attack_data=MitreAttackData("tmp/enterprise-attack/enterprise-attack.json") and then I tried to create a list all_data_components=MitreAttackData.get_datacomponents(mitre_attack_data)
2. Try to print, serialize() or MitreAttackData.print_stix_object() a stix type object from the created list
3. Error described above should occur

[scripton8]

I think the problem might be, that the list of objects returned by get_datacomponents() is that the elements in the list are custom stix objects of type <class 'stix2.custom._custom_object_builder.<locals>._CustomObject'>, that's why the serialize might fail