Issue
Adding empty collection to Supported Features will break building EffectiveModelContext. The exception thrown when build is executed is informing that the root of the issue is an invalid YANG model:
`Leaf is missing a 'type' statement [at yangtools/parser/yang-parser-impl /target/test-classes/ietf-ip/ietf-ip@2018-02-22.yang:222:11]  `

Expected solution

If is not allowed providing empty collection, add condition which will check empty collection and throw actual root of issue.