Trying to parse on a hash of symbol in ruby : I try to downcase a parsed option to match only symbol in downcase format because when I match A UPPERCASE OR meltedCASE , my parser return me a nil value :(

Don't want to have a heavy hash like [:ens, :ENS, :eNS, :enS ... etc etc

    			opts.on("-i", "--instance [INSTANCE]", [:ens, :etu], "Selectionnez l'instance de Gitlab (etu, ens)") do |instance|
				# puts instance.inspect
				Options[:instance] = instance
			end