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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 path_to_url(self, path):
 """Build URL from a path. :param path: relative path of the schema. :returns: The schema complete URL or ``None`` if not found. """

        if path not in self.schemas:
            return None
        return self.url_map.bind(
            self.app.config['JSONSCHEMAS_HOST'],
            url_scheme=self.app.config['JSONSCHEMAS_URL_SCHEME']
        ).build(
            'schema', values={'path': path}, force_external=True)