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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_objanno(self, assoc_fn):
 """Get an annotation object"""

        # Determine annotation file format from filename, if possible
        anno_type = get_anno_desc(assoc_fn, None)
        # Default annotation file format is id2gos
        if anno_type is None:
            anno_type = self.args.annofmt if self.args.annofmt else 'id2gos'
        kws = {'taxid': self.args.taxid} if anno_type == 'gene2go' else {}
        return get_objanno(assoc_fn, anno_type, **kws)