String.isEmpty() is missing.

[coderextreme]

java -cp "../j2js-compiler/libs/commons-io-1.4.jar;../j2js-compiler/libs/bcel-5.1.jar;../j2js-compiler/target/classes/" com.j2js.J2JSCompiler . "target/classes;../j2js-jre/target/classes/;../j2js-agent/target/classes/" net.x3djsonld.abox target/assemblies
[INFO] Entry point is net.x3djsonld.abox#main(java.lang.String[])void
[INFO] Creating assembly .\target\assemblies
[INFO] Resolving class path [.\target\classes, ...\j2js-jre\target\classes, ...\j2js-agent\target\classes]
[INFO] Cross-Compiling java.lang.RuntimeException
[INFO] Cross-Compiling java.lang.Throwable
[INFO] Cross-Compiling java.lang.Object
[INFO] Cross-Compiling com.j2js.prodmode.ContextImpl
[INFO] Cross-Compiling j2js.Context
[INFO] Cross-Compiling javax.script.ScriptEngine
[INFO] Cross-Compiling java.lang.System
[INFO] Cross-Compiling java.lang.String
[INFO] Cross-Compiling java.lang.CharSequence
[INFO] Cross-Compiling java.lang.StringBuilder
[INFO] Cross-Compiling java.lang.Class
[INFO] Cross-Compiling java.util.HashMap
[INFO] Cross-Compiling java.util.Map
[INFO] Cross-Compiling javascript.JSObject
[INFO] Cross-Compiling java.lang.ClassNotFoundException
[INFO] Cross-Compiling java.lang.Exception
[INFO] Cross-Compiling java.io.OutputStreamWriter
[INFO] Cross-Compiling java.io.Writer
[INFO] Cross-Compiling java.io.PrintWriter
[INFO] Cross-Compiling java.util.ArrayList
[INFO] Cross-Compiling java.util.AbstractCollection
[INFO] Cross-Compiling java.lang.Iterable
[INFO] Cross-Compiling java.util.Collection
[INFO] Cross-Compiling java.util.List
[INFO] Cross-Compiling j2js.client.Engine
[INFO] Cross-Compiling j2js.client.GenericEventListener
[INFO] Cross-Compiling java.util.Iterator
[INFO] Cross-Compiling java.lang.Integer
[INFO] Cross-Compiling java.lang.Number
[INFO] Cross-Compiling javascript.ScriptHelper
[INFO] Cross-Compiling net.x3djsonld.abox
[INFO] Cross-Compiling org.web3d.x3d.jsail.Core.X3DObject
[INFO] Cross-Compiling org.web3d.x3d.jsail.X3DConcreteStatement
[INFO] Cross-Compiling org.web3d.x3d.jsail.X3DConcreteElement
[INFO] Cross-Compiling java.io.PrintStream
[INFO] Cross-Compiling java.io.OutputStream
Exception in thread "main" java.lang.RuntimeException: No such method: java.lang.String#isEmpty()boolean
at com.j2js.Assembly.processSingle(Assembly.java:238)
at com.j2js.Assembly.processTainted(Assembly.java:220)
at com.j2js.J2JSCompiler.execute(J2JSCompiler.java:172)
at com.j2js.J2JSCompiler.execute(J2JSCompiler.java:115)
at com.j2js.J2JSCompiler.main(J2JSCompiler.java:97)