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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 parse_string(self, string):
 # type: (str) -> Dict[str, Any] """ Parse vim script string and return the AST. """

        lines = string.split('\n')

        reader = vimlparser.StringReader(lines)
        parser = vimlparser.VimLParser(self._enable_neovim)
        ast = parser.parse(reader)

        # TOPLEVEL does not have a pos, but we need pos for all nodes
        ast['pos'] = {'col': 1, 'i': 0, 'lnum': 1}

        for plugin in self.plugins:
            plugin.process(ast)

        return ast