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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 delete_keyring(service):
 """Delete an existing Ceph keyring."""

    keyring = _keyring_path(service)
    if not os.path.exists(keyring):
        log('Keyring does not exist at %s' % keyring, level=WARNING)
        return

    os.remove(keyring)
    log('Deleted ring at %s.' % keyring, level=INFO)