code: def add_defaults(self):
      old_sdist.add_defaults(self)
  
      dist = self.distribution
  
      if dist.has_data_files():
          for data in dist.data_files:
              self.filelist.extend(get_data_files(data))
  
      if dist.has_headers():
          headers = []
          for h in dist.headers:
              if isinstance(h, str):
                  headers.append(h)
              else:
                  headers.append(h[1])
          self.filelist.extend(headers)
  
      return
  
imports: import sys
  from numpy.distutils.misc_util import get_data_files
label_desc: Use image node_id 1 for calling the sdist obj's underlying member method code with example usage: obj.add_defaults() without return types