Changes in universe.py from PullRequest Inc. review
Changes in universe.py from PullRequest Inc. review

shikhar413/openmc,shikhar413/openmc,liangjg/openmc,smharper/openmc,liangjg/openmc,mit-crpg/openmc,amandalund/openmc,mit-crpg/openmc,mit-crpg/openmc,smharper/openmc,shikhar413/openmc,paulromano/openmc,smharper/openmc,smharper/openmc,paulromano/openmc,walshjon/openmc,walshjon/openmc,walshjon/openmc,walshjon/openmc,paulromano/openmc,amandalund/openmc,amandalund/openmc,liangjg/openmc,shikhar413/openmc,paulromano/openmc,mit-crpg/openmc,amandalund/openmc,liangjg/openmc