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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_boolean(self, input_string):
 """ 		Return boolean type user input 		"""


        if input_string in ('--write_roc', '--plot', '--compare'):

            # was the flag set?
            try:
                index = self.args.index(input_string) + 1
            except ValueError:
                # it wasn't, args are optional, so return the appropriate default
                return False

            # the flag was set, so return the True
            return True