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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 get_marshmallow_schema_name(self, plugin, schema):
 """Get the schema name. If the schema doesn't exist, create it. """

        try:
            return plugin.openapi.refs[schema]
        except KeyError:
            plugin.spec.definition(schema.__name__, schema=schema)
            return schema.__name__