old_contents: from charms.reactive import when, when_not, set_state, remove_state
  from charms.hadoop import get_hadoop_base
  from jujubigdata.handlers import YARN
  from jujubigdata import utils
  
  
  @when('resourcemanager.ready')
  @when_not('nodemanager.started')
  def start_nodemanager(resourcemanager):
      hadoop = get_hadoop_base()
      yarn = YARN(hadoop)
      yarn.configure_nodemanager(
          resourcemanager.resourcemanagers()[0], resourcemanager.port(),
          resourcemanager.hs_http(), resourcemanager.hs_ipc())
      utils.install_ssh_key('yarn', resourcemanager.ssh_key())
      utils.update_kv_hosts(resourcemanager.hosts_map())
      utils.manage_etc_hosts()
      yarn.start_nodemanager()
      hadoop.open_ports('nodemanager')
      set_state('nodemanager.started')
  
  
  @when('nodemanager.started')
  @when_not('resourcemanager.ready')
  def stop_nodemanager():
      hadoop = get_hadoop_base()
      yarn = YARN(hadoop)
      yarn.stop_nodemanager()
      hadoop.close_ports('nodemanager')
      remove_state('nodemanager.started')
  
new_contents: from charms.reactive import when, when_not, set_state, remove_state
  from charms.layer.hadoop_base import get_hadoop_base
  from jujubigdata.handlers import YARN
  from jujubigdata import utils
  
  
  @when('resourcemanager.ready')
  @when_not('nodemanager.started')
  def start_nodemanager(resourcemanager):
      hadoop = get_hadoop_base()
      yarn = YARN(hadoop)
      yarn.configure_nodemanager(
          resourcemanager.resourcemanagers()[0], resourcemanager.port(),
          resourcemanager.hs_http(), resourcemanager.hs_ipc())
      utils.install_ssh_key('yarn', resourcemanager.ssh_key())
      utils.update_kv_hosts(resourcemanager.hosts_map())
      utils.manage_etc_hosts()
      yarn.start_nodemanager()
      hadoop.open_ports('nodemanager')
      set_state('nodemanager.started')
  
  
  @when('nodemanager.started')
  @when_not('resourcemanager.ready')
  def stop_nodemanager():
      hadoop = get_hadoop_base()
      yarn = YARN(hadoop)
      yarn.stop_nodemanager()
      hadoop.close_ports('nodemanager')
      remove_state('nodemanager.started')
  
subject: Update charms.hadoop reference to follow convention