------------------------------------------------------- Class: Exception
      Descendents of class  Exception  are used to communicate between
       raise  methods and  rescue  statements in  begin/end  blocks.
       Exception  objects carry information about the exception---its
      type (the exception's class name), an optional descriptive string,
      and optional traceback information. Programs may subclass
       Exception  to add additional information.
 Class methods:
      exception, new
 Instance methods:
      backtrace, exception, inspect, message, set_backtrace, to_s, to_str


 ==== Exception ====
 ---- Singleton methods ----
 exception new
 ---- Instance methods ----
 backtrace exception message set_backtrace to_s to_str
 ---- Singleton methods (inherited) ----
 ---- Instance methods (inherited) ----
 == === =~ __id__ __send__ _dump _load class clone display
 dup eql? equal? extend freeze frozen? hash id initialize
 initialize_copy inspect instance_eval instance_of?
 instance_variable_get instance_variable_set
 instance_variables is_a? kind_of? marshal_dump marshal_load
 method method_missing methods nil? object_id pretty_print
 pretty_print_cycle pretty_print_instance_variables
 private_methods protected_methods public_methods
 remove_instance_variable respond_to? send
 singleton_method_added singleton_method_removed
 singleton_method_undefined singleton_methods taint tainted?
 to_a to_ary to_hash to_int type untaint