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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 ast_str(self, indent=0):
 """Return a minimal string to print a tree-like structure. Kwargs: indent (int):
 The number of indentation levels. """

        line = self.line or 0
        col = self.column or 0
        name = type(self).__name__
        spell = getattr(self, 'name', '[no spelling]')
        result = ' ({})'.format(self.result) if hasattr(self, 'result') else ''
        prefix = indent * '| '
        return '{}[{}:{}] {}{}: {}'.format(prefix, line, col,
                                           name, result, spell)