model.setGroupId( "group.id" );
model.setVersion( "1" );
Assembly assembly = new Assembly();
DependencySet set = new DependencySet();
set.setOutputFileNameMapping( "${artifact.artifactId}.${artifact.extension}" );
assembly.addDependencySet( set );
Assembly outputAssembly = interpolator.interpolate( assembly, model, Collections.EMPTY_MAP );
List outputDependencySets = outputAssembly.getDependencySets();
assertEquals( 1, outputDependencySets.size() );
DependencySet outputSet = (DependencySet) outputDependencySets.get( 0 );
assertEquals( set.getOutputFileNameMapping(), outputSet.getOutputFileNameMapping() );
}