module t
/*2.0
from m import :: T(C1)
0.2*/
//1.3
from m import T, C1
//3.1

will be transformed into

module t
/***/
from m import :: T(C1)
/***/
/*1.3
from m import T, C1
3.1*/

before scanning. In this way we achieve that the upper source can be
compiled with the 2.0 compiler as well as with the 1.3 compiler

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