this.modifiedCodebase = modifiedCodebase;
this.destinationCodebase = destinationCodebase;
File mergedDir = AppContext.RUN.fileSystem.getTemporaryDirectory("merged_codebase_");
RepositoryExpression mergedExpression = new RepositoryExpression(
new Term("merged", ImmutableMap.<String, String>of()));
this.mergedCodebase = new Codebase(mergedDir, "merged", mergedExpression);
mergedFiles = Sets.newHashSet();
failedToMergeFiles = Sets.newHashSet();
}