STEP 0:
    modifications:
        U : l1a.0.kt -> l1a.kt
        U : l1b.0.kt -> l1b.kt
        U : l1c.0.kt -> l1c.kt
    added file: l1a.kt, l1b.kt, l1c.kt
STEP 1:
    modifications:
        D : l1a.kt
        D : l1b.kt
        D : l1c.kt
    removed file: l1c.kt, l1b.kt, l1a.kt
STEP 2..3:
STEP 4:
    modifications:
        U : l1.4.kt -> l1.kt
    added file: l1.kt
STEP 5:
    modifications:
        U : l1.5.kt -> l1.kt
    modified ir: l1.kt
