パーフェクトRuby,

perfect_ruby 15章

p548 poti:todo user1$ be irb irb(main):001:0> require "todo" => true irb(main):002:0> cmd = Todo::Command.new => #<Todo::Command:0x007fbad7b10cf8> irb(main):003:0> cmd.execute => nil irb(main):004:0> cmd.create_task("create_name", "create_content") TypeError: Cannot visi</todo::command:0x007fbad7b10cf8>…