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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 write_schema_to_file(cls, schema, file_pointer=stdout, folder=MISSING, context=DEFAULT_DICT):
 """Given a Marshmallow schema, create a JSON Schema for it. Args: schema (marshmallow.Schema|str):
 The Marshmallow schema, or the Python path to one, to create the JSON schema for. Keyword Args: file_pointer (file, optional):
 The pointer to the file to write this schema to. If not provided, the schema will be dumped to ``sys.stdout``. folder (str, optional):
 The folder in which to save the JSON schema. The name of the schema file can be optionally controlled my the schema's ``Meta.json_schema_filename``. If that attribute is not set, the class's name will be used for the filename. If writing the schema to a specific file is desired, please pass in a ``file_pointer``. context (dict, optional):
 The Marshmallow context to be pushed to the schema generates the JSONSchema. Returns: dict: The JSON schema in dictionary form. """

        schema = cls._get_schema(schema)
        json_schema = cls.generate_json_schema(schema, context=context)

        if folder:
            schema_filename = getattr(
                schema.Meta,
                'json_schema_filename',
                '.'.join([schema.__class__.__name__, 'json'])
            )
            json_path = os.path.join(folder, schema_filename)
            file_pointer = open(json_path, 'w')

        json.dump(json_schema, file_pointer, indent=2)

        return json_schema