Troubleshooting Tip: netflow sampler can not be enabled on an EMAC-Vlan interface

This article describes why the error 'Netflow sampler isn't supported on EMAC VLAN interface..' is displayed when enabling 'netflow-sampler' on an EMAC-VLAN interface type. 

config system interface
    edit "emac_netflow"
      set vdom "root"
      set ip 10.11.12.13 255.255.255.0
      set type emac-vlan  <= EMAC-vlan type
      set role lan
      set snmp-index 9
      set interface "port1"
    next
end

FG_72x # config system interface

FG_72x (interface) # edit emac_netflow

FG_72x (emac_netflow) # set netflow-sampler both
Netflow sampler isn't supported on EMAC VLAN interface..