code: def get_current_roles():
      
      current_host = env.host_string
      roledefs = env.get('roledefs')
      if roledefs:
          return [role for role, hosts in six.iteritems(roledefs) if current_host in hosts]
      return []
docs: Determines the list of roles, that the current host is assigned to. If ``env.roledefs`` is not set, an empty list
      is returned.
  
      :return: List of roles of the current host.
      :rtype: list