code: def run(self):
          
          dockerfile = df_parser(self.workflow.builder.df_path, workflow=self.workflow)
          lines = dockerfile.lines
  
          # when using final dockerfile, we should use DOCKERFILE_FILENAME
          # otherwise we should use the copied version
          if self.use_final_dockerfile:
              content = 'ADD {0} {1}'.format(DOCKERFILE_FILENAME, self.df_path)
          else:
              content = 'ADD {0} {1}'.format(self.df_name, self.df_path)
  
          # put it before last instruction
          lines.insert(-1, content + '\n')
  
          dockerfile.lines = lines
  
          self.log.info("added %s", self.df_path)
  
          return content
docs: run the plugin