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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 dq_argument(self) -> str: """Parse double-quoted argument. Raises: EndOfInput: If past the end of input. """

        def escape():
            self._escape = True
            return 1
        self._escape = False                 # any escaped chars?
        self.offset += 1
        start = self.offset
        self.dfa([
            {  # state 0: argument
                "": lambda: 0,
                '"': lambda: -1,
                "\\": escape
            },
            {  # state 1: after escape
                "": lambda: 0
            }])
        self._arg += (self.unescape(self.input[start:self.offset])
                      if self._escape else self.input[start:self.offset])
        self.offset += 1