code: def exists(path, hadoop_bin=None, fs_name=None, fs_ugi=None):
      """hadoop exists"""
      hadoop_bin, fs_name, fs_ugi = parse_account(
          hadoop_bin, fs_name, fs_ugi
      )
      path = check_hadoop_path(path, hadoop_bin, fs_name, fs_ugi)
      cmd = make_base_cmd(hadoop_bin, fs_name, fs_ugi)
      cmd += " -test -e " + path
      cmd += " 2>%s ; echo $?" % ERR_LOG
      ret = int(os.popen(cmd).read().strip())
      ret = True if ret == 0 else False
      return ret
  
imports: import os
  import sys
  import json
  import time
  import math
  import collections
  import numpy
label_desc: Use image node_id 8 for calling a global function with example usage: exists(path, hadoop_bin, fs_name, fs_ugi) and returns: ret