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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 setpassword(self, pwd):
 """Set default password for encrypted files."""

        if pwd and not isinstance(pwd, bytes):
            raise TypeError("pwd: expected bytes, got %s" % type(pwd))
        if pwd:
            self.pwd = pwd
        else:
            self.pwd = None