code: def process_file(self, path, dryrun):
          
          if dryrun:
              return path
  
          # get file's current header
          with open(path, "r") as infile:
              head = infile.read(len(self.__header))
  
          # normalize line breaks
          if self.__normalize_br:
              head = head.replace("\r\n", "\n")
  
          # already contain header? skip
          if head == self.__header:
              return path
  
          # add header to file
          self.push_header(path)
  
          # return processed file
          return path
docs: Add header to all files.