Multiple quality improvements

[m-ezzat]

This pull request is focused on resolving occurrences of Sonar rules squid:S1319 - Declarations should use Java collection interfaces such as "List" rather than specific implementation classes such as "LinkedList" squid:S2325 - "private" methods that don't access instance data should be "static"

You can find more information about the issues here: https://dev.eclipse.org/sonar/coding_rules#q=squid:S1319 https://dev.eclipse.org/sonar/coding_rules#q=squid:S2325

Please let me know if you have any questions.

M-Ezzat

[ajsquared]

There are a couple of checkstyle issues after this change: https://gist.github.com/ajsquared/f8674ea4498d63fd2ed5

Would you be able to fix those up?

[m-ezzat]

@ajsquared yes, sure, thanks for informing me.

[ajsquared]

Great, thanks!