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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 close_milestone(id, **kwargs):
 """ Close a milestone. This triggers its release process. The user can optionally specify the release-date, otherwise today's date is used. If the wait parameter is specified and set to True, upon closing the milestone, we'll periodically check that the release being processed is done. Required: - id: int Optional: - wait key: bool """

    data = close_milestone_raw(id, **kwargs)
    if data:
        return utils.format_json(data)