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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_packages_of_type(self, package_types, mask=None):
 """Get packages that match a certain type. Each ordering package has a type, so return all packages that match the types we are looking for :param list package_types: List of strings representing the package type keynames we are interested in. :param string mask: Mask to specify the properties we want to retrieve """


        _filter = {
            'type': {
                'keyName': {
                    'operation': 'in',
                    'options': [
                        {'name': 'data',
                         'value': package_types}
                    ],
                },
            },
        }

        packages = self.package_svc.getAllObjects(mask=mask, filter=_filter)
        packages = self.filter_outlet_packages(packages)
        return packages