@CheckForNull
  @Override
  public Map<Path, Set<Integer>> branchChangedLines(String targetBranchName, Path projectBaseDir, Set<Path> changedFiles) {
    return branchChangedLinesWithFileMovementDetection(targetBranchName, projectBaseDir, toChangedFileByPathsMap(changedFiles));
  }
@Test
  public void branchChangedLines_returns_null_on_io_errors_of_repo_builder() {
    GitScmProvider provider = new GitScmProvider(mockCommand(), analysisWarnings, gitIgnoreCommand, system2, documentationLinkGenerator) {
      @Override
      Repository buildRepo(Path basedir) throws IOException {
        throw new IOException();
      }
    };
    assertThat(provider.branchChangedLines(BRANCH_NAME, worktree, emptySet())).isNull();
  }