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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_password(self):
 """ If password is not provided will look in environment variables for username+'password'. """

        if self.password is None:
            if os.environ.get(self.username+'password'):
                self.password = os.environ.get(self.username+'password')
            else:
                raise PasswordError(self.username)