Fixing sonar issues in whole class
https://sonar.onap.org/dashboard/index?id=org.onap.appc%3Aappc-dg-dependency-model%3Asrc%2Fmain%2Fjava%2Forg%2Fonap%2Fappc%2Fdg%2Fdependencymanager%2Fhelper%2FDependencyModelParser.java