def printable(object)
      case object
      when Array  then :array
      when Hash   then :hash
      when File   then :file
      when Dir    then :dir
      when Struct then :struct
      else object.class.to_s.gsub(/:+/, "_").downcase.to_sym
      end
    end
def printable(object)
      case object
      when Array  then :array
      when Hash   then :hash
      when File   then :file
      when Dir    then :dir
      when Struct then :struct
      else object.class.to_s.gsub(/:+/, "_").downcase.to_sym
      end
    end
Turn class name into symbol, ex: Hello::World => :hello_world. Classes that
 inherit from Array, Hash, File, Dir, and Struct are treated as the base class.
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