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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_refactor_options(self, start, end=None):
 """Return a list of options for refactoring at the given position. If `end` is also given, refactoring on a region is assumed. Each option is a dictionary of key/value pairs. The value of the key 'name' is the one to be used for get_changes. The key 'args' contains a list of additional arguments required for get_changes. """

        result = []
        for symbol in dir(self):
            if not symbol.startswith("refactor_"):
                continue
            method = getattr(self, symbol)
            if not method.refactor_notes.get('available', True):
                continue
            category = method.refactor_notes['category']
            if end is not None and category != 'Region':
                continue
            if end is None and category == 'Region':
                continue
            is_on_symbol = self._is_on_symbol(start)
            if not is_on_symbol and category in ('Symbol', 'Method'):
                continue
            requires_import = method.refactor_notes.get('only_on_imports',
                                                        False)
            if requires_import and not self._is_on_import_statement(start):
                continue
            result.append(method.refactor_notes)
        return result