ensure the field value is not null in the aggregate's reduce function
ensure the field value is not null in the aggregate's reduce function

nusco/mongoid,wyattisimo/mongoid,teaforthecat/mongoid,balauru/mongoid,hadees/mongoid,herimedia/mongoid,jordoh/mongoid,stnguyen/mongoid,trmmy/mongoid,demarque/mongoid,mzsanford/mongoid,xentek/mongoid,charliehq/mongoid,praecipula/mongoid,uranazo/mongoid,goshakkk/mongoid,cao7113/mongoid,rpocklin/mongoid,joelcogen/mongoid,luxerama/mongoid,uniiverse/mongoid,irakli-janiashvili/mongoid,janroesner/mongoid,brynary/mongoid,mash-ltd/mongoid,charliehq/mongoid,jamesalmond/mongoid,hxx/mongoid,PerfectMemory/mongoid,arnkorty/mongoid,socialreferral/mongoid,cpuguy83/mongoid,infiverve/mongoid,rogerz42892/mongoid,mattconnolly/mongoid,niedhui/mongoid,Speakol/mongoid,apptentive-engineering/mongoid,asantamar/mongoid,cao7113/mongoid,aleksclark/mongoid,kayakyakr/mongoid,Subskii/mongoid,johnny-miyake/mongoid,shotoso/mongoid,colinyoung/mongoid,hadees/mongoid,rafaelgaspar/mongoid,drfeelngood/mongoid,rinmu/mongoid,grossws/mongoid,evansagge/mongoid,fortnightlabs/mongoid,drobune/mongoid,Subskii/mongoid,CIRCUITLLC/mongoid,neerfri/mongoid,arnkorty/mongoid,parov/mongoid,chetan/mongoid,mongodb/mongoid,jtescher/mongoid,mash-ltd/mongoid,joshleitzel/mongoid,zenjoy/mongoid,joneslee85/mongoid,zBMNForks/mongoid,flada-auxv/mongoid,nullstyle/mongoid,imomoisoft/mongoid,camallen/mongoid,kcdragon/mongoid,mschulkind/mongoid,uniiverse/mongoid,simi/mongoid,bencrouse/mongoid,rinmu/mongoid,evendis/mongoid,anuprit/mongoid,dannguyen/mongoid,Azzurrio/mongoid,flexoid/mongoid,karmakaze/mongoid,nicolasblanco/mongoid,praecipula/mongoid,bjori/mongoid,kslazarev/mongoid,etomic/mongoid,joelcogen/mongoid,flexoid/mongoid,rubrikkfabrikken/mongoid,lackac/mongoid,gicappa/mongoid,500px/mongoid,SumeruSoftware/mongoid,jeyb/mongoid,xentek/mongoid,mgartner/mongoid,sepastian/mongoid,kslazarev/mongoid,kostyantyn/mongoid,fbernier/mongoid,karmakaze/mongoid,tricknotes/mongoid,codedogfish/mongoid,gregmolnar/mongoid,Codas/mongoid,Codas/mongoid,blackxored/mongoid,rubrikkfabrikken/mongoid,abezzub/mongoid,X0nic/mongoid,jtescher/mongoid,hbakhtiyor/mongoid,rogerz42892/mongoid,ErisExchange/mongoid,aleksclark/mongoid,codedogfish/mongoid,tzar/mongoid,KoanHealth/mongoid,evansagge/mongoid,asaaki/mongoid,PerfectMemory/mongoid,lucasas/mongoid,77Agency/mongoid,tagliala/mongoid,kcdragon/mongoid,rosylilly/mongoid,bearded/mongoid,mongodb/mongoid,demarque/mongoid,lucasas/mongoid,bencrouse/mongoid,hfwang/mongoid,crealytics/mongoid,estolfo/mongoid,robwil/mongoid,captain-lucas/mongoid,rosylilly/mongoid,Spaceghost/mongoid,stnguyen/mongoid,alexandru-calinoiu/mongoid,captain-lucas/mongoid,tagliala/mongoid,skiz/mongoid,Spaceghost/mongoid,eljojo/mongoid,mattconnolly/mongoid,grossws/mongoid,jasl/mongoid,herimedia/mongoid,fbernier/mongoid,amw/mongoid,luxerama/mongoid,timgluz/mongoid,ganlron/mongoid,maxd/mongoid,sepastian/mongoid,glebtv/mongoid,goshakkk/mongoid,kevinmarvin/mongoid,crowdtap/mongoid,fredjean/mongoid,aj0strow/mongoid,blackxored/mongoid,dnd/mongoid,zaithottakath/mongoid,cmpolis/mongoid,krasnoukhov/mongoid,kuadrosx/mongoid,bjori/mongoid,stevebartholomew/mongoid,imomoisoft/mongoid,jamesalmond/mongoid,abezzub/mongoid,CIRCUITLLC/mongoid,nullstyle/mongoid,zaithottakath/mongoid,mzsanford/mongoid,Azzurrio/mongoid,elia/mongoid,jstrocel/mongoid,subhashb/mongoid,aileron/mongoid,akirasosa/mongoid,mgartner/mongoid,moretea/mongoid,canvas-drw/mongoid,Welovroi/mongoid,niedhui/mongoid,zenjoy/mongoid,dustinwatson/mongoid,mongoid/mongoid,lackac/mongoid,tolsen/mongoid,X0nic/mongoid,kay-kim/mongoid,jonhyman/mongoid,hashrocketeer/mongoid,zBMNForks/mongoid,sivagollapalli/mongoid,janroesner/mongoid,aj0strow/mongoid,mongodb/mongoid,Exoth/mongoid,akirasosa/mongoid,ahoward/mongoid,irakli-janiashvili/mongoid,jbrien/mongoid,jordoh/mongoid,spiegela/mongoid,Exoth/mongoid,asantamar/mongoid,tolsen/mongoid,drfeelngood/mongoid,Speakol/mongoid,mysociety/mongoid,neerfri/mongoid,moretea/mongoid,subhashb/mongoid,Sharevari-Inc/mongoid,maxd/mongoid,mikerobe/mongoid,rpocklin/mongoid,joshsoftware/mongoid,lawrencecurtis/mongoid,dnd/mongoid,narutosanjiv/mongoid,uranazo/mongoid,robwil/mongoid,gullitmiranda/mongoid,akm/mongoid,fortnightlabs/mongoid,canvas-drw/mongoid,tricknotes/mongoid,voldy/mongoid,gregmolnar/mongoid,manikandan-kandasamy/mongoid,akm/mongoid,Numerico/mongoid,bearded/mongoid,itbakery/mongoid,Sharevari-Inc/mongoid,tombruijn/mongoid,johnnyshields/mongoid,parov/mongoid,afeld/mongoid,zanker/mongoid,dbkbali/mongoid,etomic/mongoid,matsimitsu/mongoid,matbox/mongoid,hashrocketeer/mongoid,KoanHealth/mongoid,simi/mongoid,ahoward/mongoid,jstrocel/mongoid,sivagollapalli/mongoid,dannguyen/mongoid,ganlron/mongoid,skiz/mongoid,joshleitzel/mongoid,flada-auxv/mongoid,ErisExchange/mongoid,timgluz/mongoid,glebtv/mongoid,johnnyshields/mongoid,spiegela/mongoid,narutosanjiv/mongoid,afeld/mongoid,teaforthecat/mongoid,wuboy0307/mongoid,Zhomart/mongoid,jeyb/mongoid,dbkbali/mongoid,stevebartholomew/mongoid,kostyantyn/mongoid,nusco/mongoid,kentaroi/mongoid,500px/mongoid,Welovroi/mongoid,drobune/mongoid,matbox/mongoid,tombruijn/mongoid,sideci-sample/sideci-sample-mongoid,gullitmiranda/mongoid,hbakhtiyor/mongoid,greggroth/mongoid,manikandan-kandasamy/mongoid,amw/mongoid,infiverve/mongoid,kentaroi/mongoid,krasnoukhov/mongoid,lawrencecurtis/mongoid,SumeruSoftware/mongoid,estolfo/mongoid,jordelver/mongoid,cmpolis/mongoid,trmmy/mongoid,Numerico/mongoid,kay-kim/mongoid,kuadrosx/mongoid,jonhyman/mongoid,nviennot/mongoid,elia/mongoid,hxx/mongoid,crealytics/mongoid,jordelver/mongoid,Zhomart/mongoid,balauru/mongoid,cpuguy83/mongoid,itbakery/mongoid,eljojo/mongoid,crowdtap/mongoid,matsimitsu/mongoid,hfwang/mongoid,jbrien/mongoid,camallen/mongoid,voldy/mongoid,anuprit/mongoid,kayakyakr/mongoid,lowang/mongoid,greggroth/mongoid,fredjean/mongoid,joneslee85/mongoid,mikerobe/mongoid,evendis/mongoid,johnny-miyake/mongoid,mysociety/mongoid,wuboy0307/mongoid,asaaki/mongoid,77Agency/mongoid,brynary/mongoid,mongoid/mongoid,shotoso/mongoid,joshsoftware/mongoid,aileron/mongoid,rafaelgaspar/mongoid,jasl/mongoid,apptentive-engineering/mongoid,socialreferral/mongoid,zanker/mongoid,colinyoung/mongoid,sideci-sample/sideci-sample-mongoid,tzar/mongoid,gicappa/mongoid,wyattisimo/mongoid,nviennot/mongoid,chetan/mongoid,kevinmarvin/mongoid,lowang/mongoid,alexandru-calinoiu/mongoid,mschulkind/mongoid,dustinwatson/mongoid