```ruby
module ManageIQ::Providers
  class InfraManager < BaseManager
    require_nested :Template
    require_nested :ProvisionWorkflow
    require_nested :Vm
    require_nested :VmOrTemplate

    include AvailabilityMixin

    class << model_name
      define_method(:route_key) { "ems_infras" }
      define_method(:singular_route_key) { "ems_infra" }
    end

    #
    # ems_timeouts is a general purpose proc for obtaining
    # read and open timeouts for any ems type and optional service.
    #
    # :ems
    #   :ems_redhat    (This is the type parameter for these methods)
    #     :open_timeout: 3.minutes
    #     :inventory   (This is the optional service parameter for ems_timeouts)
    #        :read_timeout: 5.minutes
    #     :service
    #        :read_timeout: 1.hour
    #
    def self.ems_timeouts(type, service = nil)
      ems_settings = ::Settings.ems[type]
      return [nil, nil] unless ems_settings

      service = service.try(:downcase)
      read_timeout = ems_settings.fetch_path([service, :read_timeout].compact).try(:to_i_with_method)
      open_timeout = ems_settings.fetch_path([service, :open_timeout].compact).try(:to_i_with_method)
      [read_timeout, open_timeout]
    end

    def validate_authentication_status
      {:available => true, :message => nil}
    end

    def validate_import_vm
      false
    end
  end
end
```

Add a method to InfraManager to retrieve Hosts without EmsCluster
user
```ruby
module ManageIQ::Providers
  class InfraManager < BaseManager
    require_nested :Template
    require_nested :ProvisionWorkflow
    require_nested :Vm
    require_nested :VmOrTemplate

    include AvailabilityMixin

    class << model_name
      define_method(:route_key) { "ems_infras" }
      define_method(:singular_route_key) { "ems_infra" }
    end

    #
    # ems_timeouts is a general purpose proc for obtaining
    # read and open timeouts for any ems type and optional service.
    #
    # :ems
    #   :ems_redhat    (This is the type parameter for these methods)
    #     :open_timeout: 3.minutes
    #     :inventory   (This is the optional service parameter for ems_timeouts)
    #        :read_timeout: 5.minutes
    #     :service
    #        :read_timeout: 1.hour
    #
    def self.ems_timeouts(type, service = nil)
      ems_settings = ::Settings.ems[type]
      return [nil, nil] unless ems_settings

      service = service.try(:downcase)
      read_timeout = ems_settings.fetch_path([service, :read_timeout].compact).try(:to_i_with_method)
      open_timeout = ems_settings.fetch_path([service, :open_timeout].compact).try(:to_i_with_method)
      [read_timeout, open_timeout]
    end

    def validate_authentication_status
      {:available => true, :message => nil}
    end

    def validate_import_vm
      false
    end

    def clusterless_hosts
      hosts.where(:ems_cluster => nil)
    end
  end
end
```
assistant