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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 app_media_url(self):
 """Get application media root from real media root URL."""

        url = None
        media_dir = self.CLOUD_BROWSER_STATIC_MEDIA_DIR
        if media_dir:
            url = os.path.join(self.MEDIA_URL, media_dir).rstrip('/') + '/'

        return url