code: def endline_handle(self, original, loc, tokens):
          
          internal_assert(len(tokens) == 1, "invalid endline tokens", tokens)
          lines = tokens[0].splitlines(True)
          if self.minify:
              lines = lines[0]
          out = []
          ln = lineno(loc, original)
          for endline in lines:
              out.append(self.wrap_line_number(self.adjust(ln)) + endline)
              ln += 1
          return "".join(out)
docs: Add line number information to end of line.