def install_alias_method(to, from, override = NO_OVERRIDE)
      to = to.id2name unless to.kind_of?(String)
      from = from.id2name unless from.kind_of?(String)

      if override == OVERRIDE_ALL or
	  (override == OVERRIDE_PRIVATE_ONLY) && !respond_to?(to) or
	  (override == NO_OVERRIDE) &&  !respond_to?(to, true)
	target = self
	(class<<self;self;end).instance_eval{
	  if target.respond_to?(to, true) && 
	      !target.respond_to?(EXCB.irb_original_method_name(to), true)
	    alias_method(EXCB.irb_original_method_name(to), to) 
	  end
	  alias_method to, from
	}
      else
	print "irb: warn: can't alias #{to} from #{from}.\n"
      end
    end
def install_alias_method(to, from, override = NO_OVERRIDE)
      to = to.id2name unless to.kind_of?(String)
      from = from.id2name unless from.kind_of?(String)

      if override == OVERRIDE_ALL or
	  (override == OVERRIDE_PRIVATE_ONLY) && !respond_to?(to) or
	  (override == NO_OVERRIDE) &&  !respond_to?(to, true)
	target = self
	(class<<self;self;end).instance_eval{
	  if target.respond_to?(to, true) && 
	      !target.respond_to?(EXCB.irb_original_method_name(to), true)
	    alias_method(EXCB.irb_original_method_name(to), to) 
	  end
	  alias_method to, from
	}
      else
	print "irb: warn: can't alias #{to} from #{from}.\n"
      end
    end
override = {NO_OVERRIDE, OVERRIDE_PRIVATE_ONLY, OVERRIDE_ALL}