I'm an newbie in corda and while starting the nodes using `call` command after the successful build, one of the nodes of corda throws us this null pointer exception shown below 

> 
> java.lang.NullPointerException
>  at co.paralleluniverse.fibers.instrument.MethodDatabase$ClassEntry.equals(MethodDatabase.java:557)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.recordSuspendableMethods(MethodDatabase.java:265)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkClass(MethodDatabase.java:327)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.getOrLoadClassEntry(MethodDatabase.java:183)
>  at co.paralleluniverse.fibers.instrument.SimpleSuspendableClassifier.isSuspendable(SimpleSuspendableClassifier.java:156)
>  at co.paralleluniverse.fibers.instrument.DefaultSuspendableClassifier.isSuspendable(DefaultSuspendableClassifier.java:47)
>  at co.paralleluniverse.fibers.instrument.CheckInstrumentationVisitor.visitMethod(CheckInstrumentationVisitor.java:130)
>  at co.paralleluniverse.asm.ClassReader.b(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkFileAndClose(MethodDatabase.java:347)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkClass(MethodDatabase.java:324)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.getOrLoadClassEntry(MethodDatabase.java:183)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.isMethodSuspendable0(MethodDatabase.java:194)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.isMethodSuspendable(MethodDatabase.java:161)
>  at co.paralleluniverse.fibers.instrument.InstrumentMethod.isSuspendableCall(InstrumentMethod.java:231)
>  at co.paralleluniverse.fibers.instrument.LabelSuspendableCallSitesClassVisitor$1.visitMethodInsn(LabelSuspendableCallSitesClassVisitor.java:64)
>  at co.paralleluniverse.asm.ClassReader.a(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.b(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:123)
>  at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:94)
>  at co.paralleluniverse.fibers.instrument.JavaAgent$Transformer.transform(JavaAgent.java:209)
>  at sun.instrument.TransformerManager.transform(Unknown Source)
>  at sun.instrument.InstrumentationImpl.transform(Unknown Source)
>  at java.lang.ClassLoader.defineClass1(Native Method)
>  at java.lang.ClassLoader.defineClass(Unknown Source)
>  at java.security.SecureClassLoader.defineClass(Unknown Source)
>  at java.net.URLClassLoader.defineClass(Unknown Source)
>  at java.net.URLClassLoader.access$100(Unknown Source)
>  at java.net.URLClassLoader$1.run(Unknown Source)
>  at java.net.URLClassLoader$1.run(Unknown Source)
>  at java.security.AccessController.doPrivileged(Native Method)
>  at java.net.URLClassLoader.findClass(Unknown Source)
>  at java.lang.ClassLoader.loadClass(Unknown Source)
>  at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
>  at java.lang.ClassLoader.loadClass(Unknown Source)
>  at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown
>  Source)
>  at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown
>  Source) [quasar] ERROR: java/lang/Thread
>  java.lang.NullPointerException
>  at co.paralleluniverse.fibers.instrument.MethodDatabase$ClassEntry.equals(MethodDatabase.java:557)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.recordSuspendableMethods(MethodDatabase.java:265)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkClass(MethodDatabase.java:327)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.getOrLoadClassEntry(MethodDatabase.java:183)
>  at co.paralleluniverse.fibers.instrument.SimpleSuspendableClassifier.isSuspendable(SimpleSuspendableClassifier.java:156)
>  at co.paralleluniverse.fibers.instrument.DefaultSuspendableClassifier.isSuspendable(DefaultSuspendableClassifier.java:47)
>  at co.paralleluniverse.fibers.instrument.CheckInstrumentationVisitor.visitMethod(CheckInstrumentationVisitor.java:130)
>  at co.paralleluniverse.asm.ClassReader.b(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkFileAndClose(MethodDatabase.java:347)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.checkClass(MethodDatabase.java:324)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.getOrLoadClassEntry(MethodDatabase.java:183)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.isMethodSuspendable0(MethodDatabase.java:194)
>  at co.paralleluniverse.fibers.instrument.MethodDatabase.isMethodSuspendable(MethodDatabase.java:161)
>  at co.paralleluniverse.fibers.instrument.InstrumentMethod.isSuspendableCall(InstrumentMethod.java:231)
>  at co.paralleluniverse.fibers.instrument.LabelSuspendableCallSitesClassVisitor$1.visitMethodInsn(LabelSuspendableCallSitesClassVisitor.java:64)
>  at co.paralleluniverse.asm.ClassReader.a(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.b(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.asm.ClassReader.accept(Unknown Source)
>  at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:123)
>  at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:94)
>  at co.paralleluniverse.fibers.instrument.JavaAgent$Transformer.transform(JavaAgent.java:209)
>  at sun.instrument.TransformerManager.transform(Unknown Source)
>  at sun.instrument.InstrumentationImpl.transform(Unknown Source)
>  at java.lang.ClassLoader.defineClass1(Native Method)
>  at java.lang.ClassLoader.defineClass(Unknown Source)
>  at java.security.SecureClassLoader.defineClass(Unknown Source)
>  at java.net.URLClassLoader.defineClass(Unknown Source)
>  at java.net.URLClassLoader.access$100(Unknown Source)
>  at java.net.URLClassLoader$1.run(Unknown Source)
>  at java.net.URLClassLoader$1.run(Unknown Source)
>  at java.security.AccessController.doPrivileged(Native Method)
>  at java.net.URLClassLoader.findClass(Unknown Source)
>  at java.lang.ClassLoader.loadClass(Unknown Source)
>  at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
>  at java.lang.ClassLoader.loadClass(Unknown Source)
>  at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown
>  Source)
>  at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown
>  Source)
> 
> 
> 

and after a brief period of time, the node completes shows it's usual corda logo and followed by H2 console url , as an normal node. is it an normal behaviour?

I did my programming using kotlin.