def query_users(options = nil)
      policy = create_policy(options, AdminPolicy, default_admin_policy)
      command = AdminCommand.new
      command.query_users(@cluster, policy)
    end
def query_users(options = nil)
      policy = create_policy(options, AdminPolicy, default_admin_policy)
      command = AdminCommand.new
      command.query_users(@cluster, policy)
    end
Retrieve all users and their roles.