docs: def write_to(self, f):
          """Writes this header to a file, in the format specified by WARC.
          """
          f.write(self.version + "\r\n")
          for name, value in self.items():
              name = name.title()
              # Use standard forms for commonly used patterns
              name = name.replace("Warc-", "WARC-").replace("-Ip-", "-IP-").replace("-Id", "-ID").replace("-Uri", "-URI")
              f.write(name)
              f.write(": ")
              f.write(value)
              f.write("\r\n")
          
          # Header ends with an extra CRLF
          f.write("\r\n")