In apex-pdp build log, we see below warnings. Those warnings should be removed.
 
13:47:57 [WARNING] 13:47:57 [WARNING] Some problems were encountered while building the effective model for org.onap.policy.apex-pdp.model:basic-model:jar:2.4.0-SNAPSHOT 13:47:57 [WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: javax.json:javax.json-api:jar -> duplicate declaration of version ${version.javax.json} @ org.onap.policy.apex-pdp.model:basic-model:[unknown-version], /w/workspace/policy-apex-pdp-master-verify-java/model/basic-model/pom.xml, line 78, column 21 13:47:57 [WARNING] 13:47:57 [WARNING] It is highly recommended to fix these problems because they threaten the stability of your build. 13:47:57 [WARNING] 13:47:57 [WARNING] For this reason, future Maven versions might no longer support building such malformed projects. 13:47:57 [WARNING]