public @NotNull PsiMigration startMigration() {
    LOG.assertTrue(myCurrentMigration == null);
    myCurrentMigration = new PsiMigrationImpl(this, JavaPsiFacade.getInstance(myProject),
                                              (PsiManagerImpl)PsiManager.getInstance(myProject));
    return myCurrentMigration;
  }
public @NotNull PsiMigration startMigration()