docstr: :param subsystem: cgroup subsystem like memory, cpu
  :return: directory where given subsystem is mounted
code: def __cgroup_mount_dir(self, subsystem):
      """
      :param subsystem: cgroup subsystem like memory, cpu
      :return: directory where given subsystem is mounted
      """
      with open("/proc/mounts", "r") as f:
          for line in f.readlines():
              split_line = re.split(r"\s+", line)
              mount_dir = split_line[1]
  
              if "cgroup" in mount_dir:
                  dirname = mount_dir.split("/")[-1]
                  subsystems = dirname.split(",")
                  if subsystem in subsystems:
                      return mount_dir
  
      assert (
          False
      ), 'Mount directory for "{}" subsystem not found'.format(
          subsystem
      )
  
file_path: neptune-client/src/neptune/common/hardware/cgroup/cgroup_filesystem_reader.py
imports: import os
  import re
label_desc: Use image node_id 8 for calling the CGroupFilesystemReader obj's underlying member method code with example usage: obj.__cgroup_mount_dir(subsystem) and returns: mount_dir