code: def append(self, other):
      self.added_files.extend(other.added_files)
      self.removed_files.extend(other.removed_files)
      self.modified_files.extend(other.modified_files)
      self.touched_files.extend(other.touched_files)
  
imports: import os
  import os.path
  import stat
  import sys
label_desc: Use image node_id 2 for calling the TreeDifference obj's underlying member method code with example usage: obj.append(other) without return types