Initialize a Collection object from a json dictionary.

def _from_dict(cls, _dict):
        """Initialize a Collection object from a json dictionary."""
        args = {}
        if 'collection_id' in _dict:
            args['collection_id'] = _dict.get('collection_id')
        if 'name' in _dict:
            args['name'] = _dict.get('name')
        if 'description' in _dict:
            args['description'] = _dict.get('description')
        if 'created' in _dict:
            args['created'] = string_to_datetime(_dict.get('created'))
        if 'updated' in _dict:
            args['updated'] = string_to_datetime(_dict.get('updated'))
        if 'status' in _dict:
            args['status'] = _dict.get('status')
        if 'configuration_id' in _dict:
            args['configuration_id'] = _dict.get('configuration_id')
        if 'language' in _dict:
            args['language'] = _dict.get('language')
        if 'document_counts' in _dict:
            args['document_counts'] = DocumentCounts._from_dict(
                _dict.get('document_counts'))
        if 'disk_usage' in _dict:
            args['disk_usage'] = CollectionDiskUsage._from_dict(
                _dict.get('disk_usage'))
        if 'training_status' in _dict:
            args['training_status'] = TrainingStatus._from_dict(
                _dict.get('training_status'))
        if 'source_crawl' in _dict:
            args['source_crawl'] = SourceStatus._from_dict(
                _dict.get('source_crawl'))
        return cls(**args)