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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 is_existing_object(did):
 """Return True if PID is for an object for which science bytes are stored locally. This excludes SIDs and PIDs for unprocessed replica requests, remote or non-existing revisions of local replicas and objects aggregated in Resource Maps. """

    return d1_gmn.app.models.ScienceObject.objects.filter(pid__did=did).exists()