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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(key, value):
 """Adds context to the currently executing request. :key: Any String identifying the request context. Example: "user_ip", "plan", "alert_count" :value: Any json-serializable type. Example: "1.1.1.1", "free", 100 :returns: nothing. """

        tr = TrackedRequest.instance()
        tr.tag(key, value)