@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_when_branch_doesnt_exist() {
    assertThat(newScmProvider().branchChangedLines("nonexistent", worktree, emptySet())).isNull();
  }