another NPE in the constructor...

exception backtrace

Java.java:724:in `call': java.lang.NullPointerException
        from JavaMethod.java:642:in `call'
        from CachingCallSite.java:269:in `cacheAndCall'
        from CachingCallSite.java:77:in `callBlock'
        from CachingCallSite.java:82:in `call'
        from ConcreteJavaProxy.java:35:in `call'
        from SuperCallSite.java:280:in `cacheAndCall'
        from SuperCallSite.java:64:in `callBlock'
        from SuperCallSite.java:69:in `call'
        from recreate_odd.rb:6:in `method__1$RUBY$initialize'
        from recreate_oddInvokermethod__1$RUBY$initializeFixed1#initialize:65535:in `call'
        from CachingCallSite.java:319:in `cacheAndCall'
        from CachingCallSite.java:157:in `callBlock'
        from CachingCallSite.java:162:in `call'
        from RubyClass.java:804:in `call'
        from DynamicMethod.java:186:in `call'
        from ConcreteJavaProxy.java:139:in `call'
        from CachingCallSite.java:309:in `cacheAndCall'
        from CachingCallSite.java:148:in `call'
        from recreate_odd.rb:9:in `__file__'
        from recreate_odd.rb:-1:in `load'
        from Ruby.java:690:in `runScript'
        from Ruby.java:573:in `runNormally'
        from Ruby.java:416:in `runFromMain'
        from Main.java:286:in `run'
        from Main.java:128:in `run'
        from Main.java:97:in `main'

gistfile1.txt

require 'java'
import javax.swing.JDialog
class ModeLessDialog < JDialog
    attr_accessor :close_button
    def initialize title_and_display_text
      super
    end
  end
ModeLessDialog.new 'hello'