MRuby::GemBox.new do |conf|
  # see summary property of each mrbgem for detail

  conf.gem :core => "mruby-sprintf"
  conf.gem :core => "mruby-print"
  conf.gem :core => "mruby-math"
  conf.gem :core => "mruby-time"
  conf.gem :core => "mruby-struct"
  conf.gem :core => "mruby-enum-ext"
  conf.gem :core => "mruby-string-ext"
  conf.gem :core => "mruby-numeric-ext"
  conf.gem :core => "mruby-array-ext"
  conf.gem :core => "mruby-hash-ext"
  conf.gem :core => "mruby-range-ext"
  conf.gem :core => "mruby-proc-ext"
  conf.gem :core => "mruby-symbol-ext"
  conf.gem :core => "mruby-random"
  conf.gem :core => "mruby-object-ext"
  conf.gem :core => "mruby-objectspace"
  conf.gem :core => "mruby-fiber"
  conf.gem :core => "mruby-enumerator"
  conf.gem :core => "mruby-toplevel-ext"
  conf.gem :core => "mruby-bin-mirb"
  conf.gem :core => "mruby-bin-mruby"
end