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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_template(template, relation):
 """ Given an entry or a category, return the path to a related template """

    if isinstance(relation, Entry):
        path = relation.category.path
    elif isinstance(relation, Category):
        path = relation.path
    else:
        path = relation

    tmpl = map_template(path, template)
    return tmpl.filename if tmpl else None