class VersionPrefixException ( Exception ) : def __init__ ( self , expected , discovered ) :
    self . expected_prefix = expected
    self . discovered_prefix = discovered
def __str__ ( self ) :
    return "str" % ( self . discovered_prefix , self . expected_prefix )

class VersionPrefixException ( Exception ) :
    def __init__ ( self , expected , discovered ) :
        self . expected_prefix = expected
        self . discovered_prefix = discovered
    def __str__ ( self ) :
        return "str" % ( self . discovered_prefix , self . expected_prefix )

次に示すpythonコードの誤りを修正しなさい。