NullPointerException thrown by md-sal for routed RPCs

Stack trace:
java.lang.NullPointerException
at org.opendaylight.controller.sal.binding.codegen.impl.RuntimeCodeGenerator$3$1$1.process(RuntimeCodeGenerator.java:234)
at org.opendaylight.controller.sal.binding.codegen.util.JavassistUtils.implementMethodsFrom(JavassistUtils.java:111)
at org.opendaylight.controller.sal.binding.codegen.impl.RuntimeCodeGenerator$3$1.process(RuntimeCodeGenerator.java:307)
at org.opendaylight.controller.sal.binding.codegen.util.JavassistUtils.createClass(JavassistUtils.java:129)
at org.opendaylight.controller.sal.binding.codegen.impl.RuntimeCodeGenerator$3.call(RuntimeCodeGenerator.java:332)
at org.opendaylight.controller.sal.binding.codegen.impl.RuntimeCodeGenerator$3.call(RuntimeCodeGenerator.java:191)
at org.opendaylight.yangtools.concepts.util.ClassLoaderUtils.withClassLoaderAndLock(ClassLoaderUtils.java:42)
at org.opendaylight.controller.sal.binding.codegen.impl.RuntimeCodeGenerator.getRouterFor(RuntimeCodeGenerator.java:344)
at org.opendaylight.controller.sal.binding.impl.RpcProviderRegistryImpl.getRpcRouter(RpcProviderRegistryImpl.java:123)
at org.opendaylight.controller.sal.binding.impl.RpcProviderRegistryImpl.addRoutedRpcImplementation(RpcProviderRegistryImpl.java:62)
at org.opendaylight.controller.sal.binding.impl.OsgiProviderContext.addRoutedRpcImplementation(OsgiProviderContext.java:43)
at org.opendaylight.protocol.integration.pcep.PcepRpcServicesRoutingTest$7.onSessionInitiated(PcepRpcServicesRoutingTest.java:206)
at org.opendaylight.controller.sal.binding.impl.BindingAwareBrokerImpl.registerProvider(BindingAwareBrokerImpl.java:96)
at org.opendaylight.protocol.integration.pcep.PcepRpcServicesRoutingTest.testRoutedRpcTopologyTunnelPcepProgrammingService(PcepRpcServicesRoutingTest.java:214)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.ops4j.pax.exam.invoker.junit.internal.ContainerTestRunner.runChild(ContainerTestRunner.java:67)
at org.ops4j.pax.exam.invoker.junit.internal.ContainerTestRunner.runChild(ContainerTestRunner.java:37)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at org.junit.runner.JUnitCore.run(JUnitCore.java:138)
at org.ops4j.pax.exam.invoker.junit.internal.JUnitProbeInvoker.invokeViaJUnit(JUnitProbeInvoker.java:123)
at org.ops4j.pax.exam.invoker.junit.internal.JUnitProbeInvoker.findAndInvoke(JUnitProbeInvoker.java:96)
at org.ops4j.pax.exam.invoker.junit.internal.JUnitProbeInvoker.call(JUnitProbeInvoker.java:72)
at org.ops4j.pax.exam.nat.internal.NativeTestContainer.call(NativeTestContainer.java:108)
at org.ops4j.pax.exam.spi.reactors.EagerSingleStagedReactor.invoke(EagerSingleStagedReactor.java:109)
at org.ops4j.pax.exam.junit.impl.ProbeRunner$2.evaluate(ProbeRunner.java:278)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.ops4j.pax.exam.junit.impl.ProbeRunner.run(ProbeRunner.java:112)
at org.ops4j.pax.exam.junit.PaxExam.run(PaxExam.java:93)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:202)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

This exception only occurs if the definition of yang structures used for routing is located in other yang module than the rpcs.

Routing structures:

grouping topology-identifier {
leaf topology-identifier

{ ext:context-reference "topology-context"; type topology-ref; }

}

typedef topology-ref

{ type instance-identifier; }

identity topology-context

{ description "Identity used to mark topology context. Used for routed rpcs"; }

Rpc with routing structures:

rpc pcep-create-p2p-tunnel {
input

{ uses tp:topology-identifier; //... }

output

{ //... }

}

A draft in bgpcep project contains the whole code needed for reproduction (https://git.opendaylight.org/gerrit/#/c/4136/ patch set 2).

Reproduce by:
Rebuild the bgpcep project with mvn clean install.
Run test PcepRpcServicesRoutingTest in integration-tests module.
Test case testRoutedRpcTopologyTunnelPcepProgrammingService should fail.

Note1: If the routing structures are located in the same module as rpcs, the exception is not thrown and everything works as expected (As demonstrated by the two other test cases located in PcepRpcServicesRoutingTest )