Groovy - such property: DELEGATE_FIRST when mapping beans

[weimeilin79]

Error with when trying to do bean mapping in Groovy.

process('processInvoice')

Caused by: groovy.lang.MissingPropertyException: No such property: DELEGATE_FIRST for class: org.apache.camel.k.loader.groovy.dsl.BeansConfiguration
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:65)
	at org.codehaus.groovy.vmplugin.v8.IndyGuardsFiltersAndSignatures.unwrap(IndyGuardsFiltersAndSignatures.java:172)
	at org.codehaus.groovy.vmplugin.v8.IndyInterface.fromCache(IndyInterface.java:318)
	at org.apache.camel.k.loader.groovy.dsl.Support$Trait$Helper$_processor_closure1.doCall(Support.groovy:26)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

Code:

beans {
    processInvoice = processor {
        it.out.body = [
            orderId: it.in.body.orderId,
            itemId: it.in.body.itemId,
            department: 'invoicing',
            datetime: System.currentTimeMillis(),
            amount: (it.in.body.quantity * it.in.body.price),
            currency: 'USD',
            invoiceId: 'B-0' + (Math.floor(1000 + Math.random() * 9999))
        ]
        it.out.headers['reply-to'] = it.in.body.username
    }
}

from('amqp:topic:incomingorders?exchangePattern=InOnly')
    .log('Invoicing Notified ${body}')
    .unmarshal().json()
    .delay(30000).asyncDelayed()
    .process('processInvoice')
    .marshal().json()
    .convertBodyTo(String.class)
    .log('H:${headers}')
    .toD('amqp:topic:notifications?exchangePattern=InOnly')
    .to('log:info')