protected String[] createMergeConflict() throws Exception {
		// create files on initial branch
		git.checkout().setName(TEST_BRANCH_NAME).call();
		writeTrashFile("dir1/a", "Hello world a");
		writeTrashFile("dir2/b", "Hello world b");
		git.add().addFilepattern(".").call();
		git.commit().setMessage("files a & b added").call();
		// create another branch and change files
		git.branchCreate().setName("branch_1").call();
		git.checkout().setName("branch_1").call();
		writeTrashFile("dir1/a", "Hello world a 1");
		writeTrashFile("dir2/b", "Hello world b 1");
		git.add().addFilepattern(".").call();
		RevCommit commit1 = git.commit()
				.setMessage("files a & b modified commit 1").call();
		// checkout initial branch
		git.checkout().setName(TEST_BRANCH_NAME).call();
		// create another branch and change files
		git.branchCreate().setName("branch_2").call();
		git.checkout().setName("branch_2").call();