here is the full exception when compiling:
Exception in thread "main" java.lang.IllegalArgumentException: Can't call public method of non-public class: public io.netty.bootstrap.AbstractBootstrap io.netty.bootstrap.AbstractBootstrap.channel(java.lang.Class), compiling:(netty.clj:31:1)
at clojure.lang.Compiler$InstanceMethodExpr.eval(Compiler.java:1453)
at clojure.lang.Compiler.compile1(Compiler.java:7153)
at clojure.lang.Compiler.compile(Compiler.java:7219)
at clojure.lang.RT.compile(RT.java:398)
at clojure.lang.RT.load(RT.java:438)
at clojure.lang.RT.load(RT.java:411)
at clojure.core$load$fn__5018.invoke(core.clj:5530)
at clojure.core$load.doInvoke(core.clj:5529)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invoke(core.clj:5336)
at clojure.core$compile$fn__5023.invoke(core.clj:5541)
at clojure.core$compile.invoke(core.clj:5540)
at user$eval7.invoke(NO_SOURCE_FILE:1)
at clojure.lang.Compiler.eval(Compiler.java:6619)
at clojure.lang.Compiler.eval(Compiler.java:6609)
at clojure.lang.Compiler.eval(Compiler.java:6582)
at clojure.core$eval.invoke(core.clj:2852)
at clojure.main$eval_opt.invoke(main.clj:308)
at clojure.main$initialize.invoke(main.clj:327)
at clojure.main$null_opt.invoke(main.clj:362)
at clojure.main$main.doInvoke(main.clj:440)
at clojure.lang.RestFn.invoke(RestFn.java:421)
at clojure.lang.Var.invoke(Var.java:419)
at clojure.lang.AFn.applyToHelper(AFn.java:163)
at clojure.lang.Var.applyTo(Var.java:532)
at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Can't call public method of non-public class: public io.netty.bootstrap.AbstractBootstrap io.netty.bootstrap.AbstractBootstrap.channel(java.lang.Class)