无法使用ActiveSupport :: Inflector进行复数化/单一化（在irb中）

irb(main):001:0> require 'active_support'
=> true
irb(main):002:0> require 'active_support/inflector/inflections'
=> true
irb(main):003:0> ActiveSupport::Inflector.pluralize('test')
=> "test"
irb(main):004:0> ActiveSupport::Inflector.singularize('tests')
=> "tests"
irb(main):005:0> ActiveSupport::Inflector.titleize('hat simulator')
=> "Hat Simulator"
<ort::Inflector.tableize("america's number one hat simulator")
=> "america's number one hat simulator"
irb(main):001:0> require 'active_support'
=> tr