module foo {
  namespace foo;
  prefix foo;

  choice foo {
    case bar {
      choice baz {
        leaf xyzzy {
          type string;
        }
      }
    }
  }
}

java.lang.NullPointerException
	at org.opendaylight.yangtools.yang.data.util.XpathStringParsingPathArgumentBuilder.nextContextNode(XpathStringParsingPathArgumentBuilder.java:114)
	at org.opendaylight.yangtools.yang.data.util.XpathStringParsingPathArgumentBuilder.computeIdentifier(XpathStringParsingPathArgumentBuilder.java:180)
	at org.opendaylight.yangtools.yang.data.util.XpathStringParsingPathArgumentBuilder.computeNextArgument(XpathStringParsingPathArgumentBuilder.java:104)
	at org.opendaylight.yangtools.yang.data.util.XpathStringParsingPathArgumentBuilder.build(XpathStringParsingPathArgumentBuilder.java:91)
	at org.opendaylight.yangtools.yang.data.util.AbstractStringInstanceIdentifierCodec.deserializeImpl(AbstractStringInstanceIdentifierCodec.java:102)
	at org.opendaylight.yangtools.yang.data.util.AbstractStringInstanceIdentifierCodec.deserializeImpl(AbstractStringInstanceIdentifierCodec.java:1)
	at org.opendaylight.yangtools.concepts.AbstractIllegalArgumentCodec.deserialize(AbstractIllegalArgumentCodec.java:30)
	at org.opendaylight.yangtools.yang.data.codec.gson.JSONInstanceIdentifierCodec.parseValue(JSONInstanceIdentifierCodec.java:71)
	at org.opendaylight.yangtools.yang.data.codec.gson.JSONInstanceIdentifierCodec.parseValue(JSONInstanceIdentifierCodec.java:1)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.translateValueByType(JsonParserStream.java:372)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.setValue(JsonParserStream.java:366)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.read(JsonParserStream.java:270)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.read(JsonParserStream.java:336)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.read(JsonParserStream.java:286)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.read(JsonParserStream.java:336)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.read(JsonParserStream.java:336)
	at org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream.parse(JsonParserStream.java:193)