observe block won't return false #322

class MyStore
  include Hyperstack::State::Observable

  def my_state
    observe { @my_state }
  end

  def my_state=(value)
    mutate { @my_state = value }
  end
end

store = MyStore.new

store.my_state
# => nil

store.my_state = true
# => true

store.my_state = false
#=> nil

# lib/hyperstack/state/observable.rb:14
          base.send(:"define_#{kind}", :observe) do |*args, &block|
            result = block && block.call || args.last
            Internal::State::Mapper.observed! self
            result
          end

# lib/hyperstack/state/observable.rb:14
          base.send(:"define_#{kind}", :observe) do |*args, &block|
            result = block_given? ? block.call : args.last
            Internal::State::Mapper.observed! self
            result
          end