VehicleSpec returns dpm::VehicleSpec:
    {dpm::VehicleSpec}
    '@Vehicle'
    ('('
        (
                ('name:' name=EString)? &
                (roads?='roads')? &
                (sky?='sky')? &
                (rivers?='rivers')? &
                (space?='space')? &
                (passengers+=Passenger )*
        )
    ')')?
;

@Vehicle(
  space sky roads rivers
  name: aMiracle
)

@Vehicle(
  name: aMiracle
  roads sky rivers space 
)

acceptor.accept(issue, 'reorder text' ,'apply default order', 'order.png',
	new ISemanticModification() {
		override apply(EObject element, IModificationContext context) throws Exception {
			val vehicle = ((element as MyObject).vehicle as VehicleSpec)
			val xtextDocument = context.xtextDocument`
			var content = '''
				@Vehicle(
					«IF vehicle.name !== null»name: «vehicle.name»«ENDIF»
					«IF vehicle.roads»roads«ENDIF»
					«IF vehicle.sky»sky«ENDIF»
					«IF vehicle.rivers»rivers«ENDIF»
					«IF vehicle.space»space«ENDIF»
					«IF vehicle.passengers.size>0»«vehicle.indices.generate»«ENDIF»
				)
			'''
			xtextDocument.replace(issue.offset, issue.length, content )									
		}
	}
)

import com.google.inject.Inject
import org.eclipse.xtext.testing.InjectWith
import org.eclipse.xtext.testing.extensions.InjectionExtension
import org.eclipse.xtext.testing.util.ParseHelper
import org.junit.jupiter.api.Assertions
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.^extension.ExtendWith
import org.xtext.example.mydsl.myDsl.VehicleSpec
import org.eclipse.xtext.serializer.ISerializer
import org.eclipse.xtext.nodemodel.util.NodeModelUtils

@ExtendWith(InjectionExtension)
@InjectWith(MyDslInjectorProvider)
class MyDslParsingTest {
	@Inject
	ParseHelper<VehicleSpec> parseHelper
	
	@Inject
	ISerializer ser
	
	@Test
	def void loadModel() {
		val result = parseHelper.parse('''
			@Vehicle(
			  space sky roads rivers
			  name: aMiracle
			)
		''')
		Assertions.assertNotNull(result)
		val errors = result.eResource.errors
		Assertions.assertTrue(errors.isEmpty, '''Unexpected errors: «errors.join(", ")»''')
		println(ser.serialize(result))
		// remove node model
		result.eAdapters().remove(NodeModelUtils.getNode(result));
		println(ser.serialize(result))
	}
}