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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 add_timeline_to_sketch(self, sketch_id, index_id):
 """Associate the specified timeline and sketch. Args: sketch_id (int):
 ID of sketch index_id (int):
 ID of timeline to add to sketch """

    resource_url = '{0:s}/sketches/{1:d}/timelines/'.format(
        self.api_base_url, sketch_id)
    form_data = {'timeline': [index_id]}
    self.session.post(resource_url, json=form_data)