docs: def copy(copy_entry: FILE_COPY_ENTRY):
      """
      Copies the specified file from its source location to its destination
      location.
      """
      source_path = environ.paths.clean(copy_entry.source)
      output_path = environ.paths.clean(copy_entry.destination)
      copier = shutil.copy2 if os.path.isfile(source_path) else shutil.copytree
      make_output_directory(output_path)
  
      for i in range(3):
          try:
              copier(source_path, output_path)
              return
          except Exception:
              time.sleep(0.5)
  
      raise IOError('Unable to copy "{source}" to "{destination}"'.format(
          source=source_path,
          destination=output_path
      ))