asciidoctor/asciidoctorj — pull request #169 by benevans (2014-07-31 15:37:07+00:00)
Title: Add default constructor to CaseInsensitiveMap so JRuby can dup() it.

I ran into this on 1.5.0.preview.7 when trying to pass an attributes map obtained from `DocumentHeader.getAttributes()` into `readDocumentStructure()`:
````java
import org.asciidoctor.Asciidoctor;
import org.asciidoctor.OptionsBuilder;
import org.asciidoctor.ast.DocumentHeader;

public class Test {

public static void main(String[] args) {
Asciidoctor asciidoctor = Asciidoctor.Factory.create();
DocumentHeader hdr = asciidoctor.readDocumentHeader("foo");
asciidoctor.readDocumentStructure("bar", OptionsBuilder.options().attributes(hdr.getAttributes()).asMap());
}
}
````

JRuby blows up with this error:
````
Exception in thread "main" org.jruby.exceptions.RaiseException: (NotImplementedError) can't dup Map of type org.asciidoctor.internal.CaseInsensitiveMap
at org.jruby.RubyKernel.dup(org/jruby/RubyKernel.java:2062)
at RUBY.load(jar:file:/home/ben/.gradle/caches/modules-2/files-2.1/org.asciidoctor/asciidoctorj/1.5.0.preview.7/946801c962a23808795becce2f6a27f44674230c/asciidoctorj-1.5.0.preview.7.jar!/gems/asciidoctor-1.5.0.preview.7/lib/asciidoctor.rb:1217)
at RUBY.load(