# File erubis/util.rb, line 11
  def not_implemented     #:doc:
    backtrace = caller()
    method_name = (backtrace.shift =~ /`(\w+)'$/) && $1
    mesg = "class #{self.class.name} must implement abstract method '#{method_name}()'."
    #mesg = "#{self.class.name}##{method_name}() is not implemented."
    err = NotImplementedError.new mesg
    err.set_backtrace backtrace
    raise err
  end