docs: def get_process_tag(program, ccd, version='p'):
      """
      make a process tag have a suffix indicating which ccd its for.
      @param program: Name of the process that a tag is built for.
      @param ccd: the CCD number that this process ran on.
      @param version: The version of the exposure (s, p, o) that the process ran on.
      @return: The string that represents the processing tag.
      """
      return "%s_%s%s" % (program, str(version), str(ccd).zfill(2))