Returns the entity class registered for the given registered resource.

    :param resource: registered resource
    :type collection: class implementing or instance providing a registered
        resource interface.
    :return: entity class
        (class implementing `everest.entities.interfaces.IEntity`)

def get_entity_class(resource):
    """
    Returns the entity class registered for the given registered resource.

    :param resource: registered resource
    :type collection: class implementing or instance providing a registered
        resource interface.
    :return: entity class
        (class implementing `everest.entities.interfaces.IEntity`)
    """
    reg = get_current_registry()
    if IInterface in provided_by(resource):
        ent_cls = reg.getUtility(resource, name='entity-class')
    else:
        ent_cls = reg.getAdapter(resource, IEntity, name='entity-class')
    return ent_cls