say-hello.rb

class Person

   private

   SPEAK = ENV['ENABLE_SPEAK'] == 'true'

   public

   def speak
     return 'WWWWWAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHH' unless SPEAK
    "Luke, I am Your Father"
   end

   def speak_2
     return 'WWWWWAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHH' unless ENV['ENABLE_SPEAK'] == 'true'
    "Luke, I am Your Father"
   end
end

person = Person.new
puts person.speak
puts person.speak_2

ENV['ENABLE_SPEAK'] = 'true'

person = Person.new
puts person.speak
puts person.speak_2