code: def _parse_proc_pid_cgroup(content):
      
      for ownCgroup in content:
          #each line is "id:subsystem,subsystem:path"
          ownCgroup = ownCgroup.strip().split(':')
          try:
              path = ownCgroup[2][1:] # remove leading /
          except IndexError:
              raise IndexError("index out of range for " + str(ownCgroup))
          for subsystem in ownCgroup[1].split(','):
              yield (subsystem, path)
docs: Parse a /proc/*/cgroup file into tuples of (subsystem,cgroup).
      @param content: An iterable over the lines of the file.
      @return: a generator of tuples