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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 visit_str(self, node, _):
 """Regex rule for quoted string allowing escaped quotes inside. Arguments --------- node : parsimonious.nodes.Node. _ (children) : list, unused Result ------ str The wanted string, with quoted characters unquoted. Example ------- 'foo' 'foo' "foo b'ar" "foo b'ar" "foo b'ar" Notes ----- The regex works this way: Two quotes (single or double, the starting one and the ending one should be the same) surrounding zero or more of "any character that's not a quote (same as the starting/ending ones) or a backslash" or "a backslash followed by any character". """


        # remove surrounding quotes and remove single backslashes
        return self.visit_str.re_single_backslash.sub('', node.text[1:-1])