Empty JSon object lead to NPE

Similar to https://jira.talendforge.org/browse/TCOMP-1197

When testing tacokit component using beam there is an NPE in this code:

package org.talend.sdk.component.runtime.beam.spi.record;
public class SchemaIdGenerator {
...
private static long fingerprint(final List<Schema.Field> fields) {
return SchemaNormalization
.parsingFingerprint64(Schema
.createRecord(fields
.stream()
...

'fields' is a Null
-------------------------------
it happens when I return this JsonObject from 'next' @Producer:

{"createdDateTime":"2018-10-30T06:55:37Z","id":"01QB6TFI56Y2GOVW7725BZO354PWSELRRZ","lastModifiedDateTime":"2018-11-29T14:00:18Z","name":"root","webUrl":"https://talend365-my.sharepoint.com/personal/rd_dev_component_talend_com/Documents","size":126,"parentReference":

{"driveId":"b!vA0VBwRaJ02UHlYb05Xs2JbkVJuJpvtBspftiL_xIAXVyJGFANHlRJwop0FYRGR2","driveType":"business"}

,"fileSystemInfo":{"createdDateTime":"2018-10-30T06:55:37Z","lastModifiedDateTime":"2018-11-29T14:00:18Z"},"folder":{"childCount":1},"root":{}}

 

The problem is with empty 'root' property.
-------------------------------
and the stack trace:

---------------------------------
<component-api.version>1.1.1</component-api.version>
<component-runtime.version>1.1.3-SNAPSHOT</component-runtime.version>
<beam.version>2.6.0</beam.version>