Prior to 2.1, if you defined a method, you received nil as a return value: irb(main):001:0> def fun irb(main):002:1> end => nil With 2.1, the method definition returns a symbol for the method name: irb(main):001:0> def fun irb(main):002:1> end => :fun One impact of this is that the following pattern for declaring a single private […]