UMLPackage.Literals.MODEL throws java.lang.NoClassDefFoundError error

I would like to get the state machine from .uml file created by papyrus. I am parsing the model.uml file using the code below.

    ResourceSet set = new ResourceSetImpl();
set.getResourceFactoryRegistry().getExtensionToFactoryMap()
    .put(UMLResource.FILE_EXTENSION, UMLResource.Factory.INSTANCE);
set.getResourceFactoryRegistry().getExtensionToFactoryMap()
    .put(UMLResource.FILE_EXTENSION, UMLResource.Factory.INSTANCE);
Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap()
    .put(UMLResource.FILE_EXTENSION, UMLResource.Factory.INSTANCE);
Resource res = set.getResource(URI.createFileURI("resources/model.uml"), true);
EcoreUtil.resolveAll(res);
System.out.println(res.getContents().get(0)); 

This code works fine and prints the content. But when I try to cast it to Model class using the code below

Model model = (Model) EcoreUtil.getObjectByType(res.getContents(),UMLPackage.Literals.MODEL);

It throws this exception,

Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/uml2/types/TypesPackage
at org.eclipse.uml2.uml.internal.impl.UMLPackageImpl.init(UMLPackageImpl.java:1907)
at org.eclipse.uml2.uml.UMLPackage.<clinit>(UMLPackage.java:83)
at org.eclipse.uml2.uml.UMLPackage$Literals.<clinit>(UMLPackage.java:28779)
at mp.m2bt.BTGenerator.main(BTGenerator.java:49)
Caused by: java.lang.ClassNotFoundException: org.eclipse.uml2.types.TypesPackage
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)

I am not sure if I am missing anything. I think the problem is in UMLPackage.Literals.MODEL. So, Can anybody help me to fix this issue and get the state machines from the model.

You need the jar org.eclipse.uml2.types in your classpath. This is why the type org.eclipse.uml2.types.TypesPackage cannot be found.