class field can be replaced by local variable

[noobyu6]

What this PR does / why we need it:

class fields can be replaced by local variables which can save memory

Which issue(s) this PR closes:

• Closes Feature Request/Idea:Code optimization suggestions #8771

Special notes for your reviewer:

no

Suggestions on how to test this:

code review

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

no

Is there a release notes update needed for this change?:

reduce memory usage

Additional documentation:

[coveralls]

Coverage: 20.009%. Remained the same when pulling 80ad3db on noobyu6:develop into 1aabf69 on IQSS:develop.

[mreekie]

Prio meeting with Stefano.

• Moved from Community Backlog to ordered backlog

[pdurbin]

@noobyu6 thanks for the pull request. Next time, please create a branch called something other than "develop".

I just merged the latest from origin/develop into noobyu6/develop but it's weird. Here are my notes:

# do all this in /tmp away from your normal code
cd /tmp
git clone git@github.com:IQSS/dataverse.git
cd dataverse
git remote add noobyu6 git@github.com:noobyu6/dataverse.git
git fetch noobyu6
# make a new branch not called develop (dev2)
git co noobyu6/develop -b dev2
git merge origin/develop
# delete the real develop branch (!) locally
git branch -d develop
# checkout dev2 (false develop)  as develop for now
git co -b develop
# push the false develop to the contributor's fork (to the PR)
git push noobyu6 develop 
cd ..
# delete the tmp space
rm -rf /tmp/dataverse

Anyway, I'm just waiting for the tests to pass. Then I'll move this to QA. Thanks again.

[pdurbin]

Tests are passing. Approved!