Caused by: java.lang.NullPointerException
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.SimpleNamespaceContext.addTo(SimpleNamespaceContext.java:50)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.NamespaceStorageSupport.addToNamespace(NamespaceStorageSupport.java:69)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementContextBase.addToNs(StatementContextBase.java:349)
 at org.opendaylight.yangtools.yang.parser.rfc7950/org.opendaylight.yangtools.yang.parser.rfc7950.stmt.BaseSchemaTreeStatementSupport.onStatementAdded(BaseSchemaTreeStatementSupport.java:37)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementDefinitionContext.onStatementAdded(StatementDefinitionContext.java:68)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementContextBase.childCopyOf(StatementContextBase.java:904)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementContextBase.childCopyOf(StatementContextBase.java:868)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementContextBase.copyAsChildOf(StatementContextBase.java:853)
 at org.opendaylight.yangtools.yang.parser.rfc7950/org.opendaylight.yangtools.yang.parser.rfc7950.stmt.uses.UsesStatementSupport.copyFromSourceToTarget(UsesStatementSupport.java:212)
 at org.opendaylight.yangtools.yang.parser.rfc7950/org.opendaylight.yangtools.yang.parser.rfc7950.stmt.uses.UsesStatementSupport$1.apply(UsesStatementSupport.java:112)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.ModifierImpl.applyAction(ModifierImpl.java:91)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.ModifierImpl.tryApply(ModifierImpl.java:150)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.SourceSpecificContext.tryToProgress(SourceSpecificContext.java:310)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.SourceSpecificContext.tryToCompletePhase(SourceSpecificContext.java:284)
 at org.opendaylight.yangtools.yang.parser.reactor/org.opendaylight.yangtools.yang.parser.stmt.reactor.BuildGlobalContext.completePhaseActions(BuildGlobalContext.java:390)
 ... 33 more