Add RDD.toDebugString.
Add RDD.toDebugString.

Original idea by Nathan Kronenfeld.

tengpeng/spark,dongjoon-hyun/spark,stanzhai/spark,sahilTakiar/spark,ericvandenbergfb/spark,zero323/spark,spark-test/spark,narahari92/spark,goldmedal/spark,zero323/spark,brad-kaiser/spark,gengliangwang/spark,loneknightpy/spark,facaiy/spark,vinodkc/spark,akopich/spark,wzhfy/spark,publicRoman/spark,mzl9039/spark,zzcclp/spark,UndeadBaneGitHub/spark,nilsgrabbert/spark,sahilTakiar/spark,guoxiaolongzte/spark,setjet/spark,alunarbeach/spark,apache/spark,brad-kaiser/spark,rednaxelafx/apache-spark,xflin/spark,ptkool/spark,cloud-fan/spark,nlalevee/spark,ericvandenbergfb/spark,lvdongr/spark,pgandhi999/spark,icexelloss/spark,jiangxb1987/spark,shuangshuangwang/spark,yanboliang/spark,joseph-torres/spark,LantaoJin/spark,hvanhovell/spark,JoshRosen/spark,caneGuy/spark,brad-kaiser/spark,panfengfeng/spark,michalsenkyr/spark,akopich/spark,jkbradley/spark,xuanyuanking/spark,1haodian/spark,cin/spark,alunarbeach/spark,andrewor14/iolap,darionyaphet/spark,BryanCutler/spark,mzl9039/spark,skonto/spark,rekhajoshm/spark,dbtsai/spark,akopich/spark,cloudera/spark,zhouyejoe/spark,stanzhai/spark,someorz/spark,sureshthalamati/spark,andrewor14/spark,jiangxb1987/spark,ron8hu/spark,highfei2011/spark,gioenn/xSpark,mike0sv/spark,SnappyDataInc/spark,Panos-Bletsos/spark-cost-model-optimizer,patrick-nicholson/spark,haowu80s/spark,WindCanDie/spark,kissmetrics/spark,wgpshashank/spark,nlalevee/spark,icexelloss/spark,hvanhovell/spark,JerryLead/spark,liutang123/spark,JoshRosen/spark,MLnick/spark,kiszk/spark,witgo/spark,LantaoJin/spark,lxsmnv/spark,mzl9039/spark,MLnick/spark,facaiy/spark,goldmedal/spark,vax11780/spark,wangyum/spark,HyukjinKwon/spark,aosagie/spark,metamx/spark,ahnqirage/spark,jiangxb1987/spark,cloud-fan/spark,ddna1021/spark,huang1900/spark,hhbyyh/spark,rjpower/spark,byakuinss/spark,narahari92/spark,setjet/spark,WindCanDie/spark,kiszk/spark,eyalfa/spark,ericvandenbergfb/spark,cloudera/spark,guoxiaolongzte/spark,srowen/spark,guoxiaolongzte/spark,highfei2011/spark,andrewor14/iolap,janewangfb/spark,chuckchen/spark,aokolnychyi/spark,lyogavin/spark,mzl9039/spark,andrewor14/iolap,shuangshuangwang/spark,akopich/spark,chuckchen/spark,wzhfy/spark,bdrillard/spark,someorz/spark,hhbyyh/spark,caneGuy/spark,minixalpha/spark,JoshRosen/spark,srowen/spark,rednaxelafx/apache-spark,cloud-fan/spark,darionyaphet/spark,dhruve/spark,mahak/spark,gioenn/xSpark,pgandhi999/spark,shubhamchopra/spark,spark-test/spark,matthewfranglen/spark,HyukjinKwon/spark,lxsmnv/spark,yanboliang/spark,bOOm-X/spark,michalsenkyr/spark,lyogavin/spark,wangyum/spark,aray/spark,ioana-delaney/spark,ddna1021/spark,JoshRosen/spark,aray/spark,pgandhi999/spark,bravo-zhang/spark,mdespriee/spark,map222/spark,lvdongr/spark,SnappyDataInc/spark,holdenk/spark,taroplus/spark,cloudera/spark,wzhfy/spark,Aegeaner/spark,bravo-zhang/spark,map222/spark,alunarbeach/spark,sahilTakiar/spark,jiangxb1987/spark,pgandhi999/spark,rekhajoshm/spark,1haodian/spark,shubhamchopra/spark,esi-mineset/spark,rednaxelafx/apache-spark,saturday-shi/spark,techaddict/spark,WindCanDie/spark,metamx/spark,bOOm-X/spark,loneknightpy/spark,liutang123/spark,panfengfeng/spark,WeichenXu123/spark,srowen/spark,JoshRosen/spark,dotunolafunmiloye/spark,haowu80s/spark,aray/spark,holdenk/spark,JerryLead/spark,caneGuy/spark,minixalpha/spark,mike0sv/spark,gengliangwang/spark,SHASHANKB/spark,WeichenXu123/spark,pgandhi999/spark,BryanCutler/spark,wangmiao1981/spark,actuaryzhang/spark,xflin/spark,vax11780/spark,actuaryzhang/spark,darionyaphet/spark,markhamstra/spark,andrewor14/spark,hvanhovell/spark,gioenn/xSpark,skonto/spark,xflin/spark,xuanyuanking/spark,markhamstra/spark,ajaysaini725/spark,lxsmnv/spark,byakuinss/spark,ptkool/spark,WeichenXu123/spark,ptkool/spark,milliman/spark,mzl9039/spark,ahnqirage/spark,kimoonkim/spark,holdenk/spark,nchammas/spark,aray/spark,haowu80s/spark,tengpeng/spark,yanboliang/spark,yanboliang/spark,zhouyejoe/spark,saturday-shi/spark,JerryLead/spark,metamx/spark,publicRoman/spark,nilsgrabbert/spark,haowu80s/spark,taroplus/spark,ajaysaini725/spark,techaddict/spark,tengpeng/spark,1haodian/spark,techaddict/spark,saturday-shi/spark,janewangfb/spark,byakuinss/spark,aosagie/spark,stanzhai/spark,bdrillard/spark,sryza/spark,gengliangwang/spark,nlalevee/spark,ron8hu/spark,sryza/spark,actuaryzhang/spark,aokolnychyi/spark,loneknightpy/spark,ahnqirage/spark,ioana-delaney/spark,vax11780/spark,jianran/spark,sureshthalamati/spark,shuangshuangwang/spark,hvanhovell/spark,Panos-Bletsos/spark-cost-model-optimizer,apache/spark,liutang123/spark,ibm-research-ireland/sparkoscope,rikima/spark,UndeadBaneGitHub/spark,liyichao/spark,wgpshashank/spark,esi-mineset/spark,zero323/spark,mahak/spark,ibm-research-ireland/sparkoscope,brad-kaiser/spark,vinodkc/spark,zhouyejoe/spark,jkbradley/spark,ajaysaini725/spark,shuangshuangwang/spark,eyalfa/spark,liyichao/spark,shaneknapp/spark,bOOm-X/spark,WindCanDie/spark,rekhajoshm/spark,eyalfa/spark,icexelloss/spark,dongjoon-hyun/spark,adrian-ionescu/apache-spark,liyichao/spark,esi-mineset/spark,srowen/spark,huang1900/spark,mzl9039/spark,andrewor14/spark,aray/spark,sahilTakiar/spark,MLnick/spark,cin/spark,byakuinss/spark,pgandhi999/spark,kiszk/spark,kimoonkim/spark,UndeadBaneGitHub/spark,someorz/spark,tejasapatil/spark,mkolod/incubator-spark,BryanCutler/spark,ioana-delaney/spark,setjet/spark,chuckchen/spark,saltstar/spark,rikima/spark,ueshin/apache-spark,gengliangwang/spark,minixalpha/spark,joseph-torres/spark,big-pegasus/spark,adrian-ionescu/apache-spark,techaddict/spark,shuangshuangwang/spark,ibm-research-ireland/sparkoscope,kissmetrics/spark,liyichao/spark,dongjoon-hyun/spark,mahak/spark,spark-test/spark,nilsgrabbert/spark,koeninger/spark,goldmedal/spark,markhamstra/spark,someorz/spark,JerryLead/spark,mkolod/incubator-spark,big-pegasus/spark,SnappyDataInc/spark,joseph-torres/spark,patrick-nicholson/spark,kiszk/spark,zzcclp/spark,zero323/spark,jrshust/spark,gioenn/xSpark,dbtsai/spark,saltstar/spark,jrshust/spark,wangmiao1981/spark,ddna1021/spark,sachintyagi22/spark,facaiy/spark,mahak/spark,rekhajoshm/spark,mkolod/incubator-spark,dhruve/spark,zuotingbing/spark,mike0sv/spark,WeichenXu123/spark,hhbyyh/spark,rezasafi/spark,jianran/spark,tengpeng/spark,narahari92/spark,panfengfeng/spark,alunarbeach/spark,markhamstra/spark,ron8hu/spark,spark-test/spark,ericvandenbergfb/spark,jlopezmalla/spark,panfengfeng/spark,BryanCutler/spark,ericvandenbergfb/spark,skonto/spark,esi-mineset/spark,shaneknapp/spark,pgandhi999/spark,michalsenkyr/spark,aray/spark,patrick-nicholson/spark,LantaoJin/spark,poffuomo/spark,szhem/spark,wangmiao1981/spark,saturday-shi/spark,WindCanDie/spark,spark-test/spark,apache-spark-on-k8s/spark,someorz/spark,someorz/spark,goldmedal/spark,guoxiaolongzte/spark,holdenk/spark,nilsgrabbert/spark,kevinyu98/spark,goldmedal/spark,vinodkc/spark,jkbradley/spark,xuanyuanking/spark,JoshRosen/spark,sachintyagi22/spark,aosagie/spark,publicRoman/spark,milliman/spark,apache/spark,ConeyLiu/spark,bravo-zhang/spark,adrian-ionescu/apache-spark,aokolnychyi/spark,SnappyDataInc/spark,brad-kaiser/spark,adrian-ionescu/apache-spark,dbtsai/spark,setjet/spark,icexelloss/spark,MLnick/spark,stanzhai/spark,rednaxelafx/apache-spark,witgo/spark,janewangfb/spark,dotunolafunmiloye/spark,BryanCutler/spark,dhruve/spark,narahari92/spark,dongjoon-hyun/spark,minixalpha/spark,jiangxb1987/spark,minixalpha/spark,koeninger/spark,kimoonkim/spark,rezasafi/spark,sryza/spark,patrick-nicholson/spark,kiszk/spark,pronix/spark,ron8hu/spark,hvanhovell/spark,huang1900/spark,aokolnychyi/spark,ConeyLiu/spark,alunarbeach/spark,jianran/spark,narahari92/spark,xuanyuanking/spark,shuangshuangwang/spark,ron8hu/spark,milliman/spark,mdespriee/spark,sachintyagi22/spark,liyichao/spark,patrick-nicholson/spark,ahnqirage/spark,maropu/spark,mkolod/incubator-spark,highfei2011/spark,kissmetrics/spark,wzhfy/spark,zzcclp/spark,xflin/spark,eyalfa/spark,stanzhai/spark,kevinyu98/spark,apache/spark,highfei2011/spark,mdespriee/spark,debugger87/spark,shaneknapp/spark,debugger87/spark,rezasafi/spark,JerryLead/spark,ddna1021/spark,cin/spark,ibm-research-ireland/sparkoscope,highfei2011/spark,wangmiao1981/spark,actuaryzhang/spark,bOOm-X/spark,poffuomo/spark,alunarbeach/spark,actuaryzhang/spark,dbtsai/spark,zhouyejoe/spark,aosagie/spark,rekhajoshm/spark,chuckchen/spark,facaiy/spark,zzcclp/spark,andrewor14/spark,ConeyLiu/spark,rednaxelafx/apache-spark,janewangfb/spark,publicRoman/spark,ibm-research-ireland/sparkoscope,alunarbeach/spark,wangmiao1981/spark,caneGuy/spark,poffuomo/spark,lxsmnv/spark,rekhajoshm/spark,akopich/spark,wangyum/spark,sureshthalamati/spark,actuaryzhang/spark,wzhfy/spark,haowu80s/spark,Panos-Bletsos/spark-cost-model-optimizer,bravo-zhang/spark,apache-spark-on-k8s/spark,minixalpha/spark,SHASHANKB/spark,eyalfa/spark,zuotingbing/spark,darionyaphet/spark,big-pegasus/spark,cloud-fan/spark,dotunolafunmiloye/spark,guoxiaolongzte/spark,brad-kaiser/spark,ConeyLiu/spark,vax11780/spark,gioenn/xSpark,tejasapatil/spark,dhruve/spark,taroplus/spark,map222/spark,cloud-fan/spark,Panos-Bletsos/spark-cost-model-optimizer,sureshthalamati/spark,jrshust/spark,rednaxelafx/apache-spark,gengliangwang/spark,Aegeaner/spark,metamx/spark,Panos-Bletsos/spark-cost-model-optimizer,spark-test/spark,nchammas/spark,highfei2011/spark,haowu80s/spark,zhouyejoe/spark,andrewor14/spark,rjpower/spark,skonto/spark,kissmetrics/spark,saltstar/spark,szhem/spark,milliman/spark,lvdongr/spark,michalsenkyr/spark,chuckchen/spark,ConeyLiu/spark,publicRoman/spark,ioana-delaney/spark,mahak/spark,wzhfy/spark,markhamstra/spark,rjpower/spark,gengliangwang/spark,bravo-zhang/spark,xflin/spark,jlopezmalla/spark,jkbradley/spark,spark-test/spark,mzl9039/spark,ron8hu/spark,caneGuy/spark,kissmetrics/spark,hhbyyh/spark,andrewor14/iolap,SnappyDataInc/spark,bOOm-X/spark,tejasapatil/spark,shubhamchopra/spark,SnappyDataInc/spark,SHASHANKB/spark,maropu/spark,Aegeaner/spark,MLnick/spark,janewangfb/spark,dbtsai/spark,nchammas/spark,ddna1021/spark,liutang123/spark,andrewor14/spark,panfengfeng/spark,rikima/spark,mike0sv/spark,WeichenXu123/spark,bravo-zhang/spark,caneGuy/spark,lyogavin/spark,ahnqirage/spark,wzhfy/spark,debugger87/spark,apache/spark,apache-spark-on-k8s/spark,big-pegasus/spark,publicRoman/spark,nlalevee/spark,kimoonkim/spark,ericvandenbergfb/spark,maropu/spark,jlopezmalla/spark,liyichao/spark,ueshin/apache-spark,map222/spark,loneknightpy/spark,wgpshashank/spark,bdrillard/spark,dhruve/spark,sahilTakiar/spark,rezasafi/spark,WeichenXu123/spark,wangyum/spark,map222/spark,ioana-delaney/spark,gengliangwang/spark,xuanyuanking/spark,ptkool/spark,highfei2011/spark,rekhajoshm/spark,kevinyu98/spark,lvdongr/spark,sureshthalamati/spark,milliman/spark,dbtsai/spark,tejasapatil/spark,panfengfeng/spark,UndeadBaneGitHub/spark,shubhamchopra/spark,kevinyu98/spark,ajaysaini725/spark,Panos-Bletsos/spark-cost-model-optimizer,jianran/spark,byakuinss/spark,sryza/spark,jianran/spark,akopich/spark,map222/spark,xflin/spark,vinodkc/spark,techaddict/spark,srowen/spark,UndeadBaneGitHub/spark,shubhamchopra/spark,setjet/spark,jkbradley/spark,zzcclp/spark,kiszk/spark,koeninger/spark,cloudera/spark,kevinyu98/spark,pronix/spark,maropu/spark,wangyum/spark,dongjoon-hyun/spark,zzcclp/spark,Aegeaner/spark,kissmetrics/spark,wangmiao1981/spark,witgo/spark,holdenk/spark,metamx/spark,Aegeaner/spark,ericvandenbergfb/spark,big-pegasus/spark,saltstar/spark,andrewor14/iolap,nchammas/spark,aosagie/spark,srowen/spark,HyukjinKwon/spark,huang1900/spark,apache/spark,sureshthalamati/spark,andrewor14/iolap,ConeyLiu/spark,zuotingbing/spark,hhbyyh/spark,milliman/spark,rjpower/spark,nchammas/spark,jiangxb1987/spark,shaneknapp/spark,lvdongr/spark,loneknightpy/spark,ron8hu/spark,mdespriee/spark,ibm-research-ireland/sparkoscope,pronix/spark,cin/spark,adrian-ionescu/apache-spark,joseph-torres/spark,darionyaphet/spark,poffuomo/spark,zero323/spark,setjet/spark,debugger87/spark,dongjoon-hyun/spark,vinodkc/spark,jiangxb1987/spark,andrewor14/iolap,shuangshuangwang/spark,shaneknapp/spark,1haodian/spark,rikima/spark,chuckchen/spark,metamx/spark,apache-spark-on-k8s/spark,witgo/spark,joseph-torres/spark,jrshust/spark,rednaxelafx/apache-spark,poffuomo/spark,mkolod/incubator-spark,mike0sv/spark,loneknightpy/spark,tengpeng/spark,saltstar/spark,HyukjinKwon/spark,adrian-ionescu/apache-spark,akopich/spark,saltstar/spark,aosagie/spark,zuotingbing/spark,yanboliang/spark,patrick-nicholson/spark,cloud-fan/spark,nchammas/spark,shubhamchopra/spark,sureshthalamati/spark,icexelloss/spark,techaddict/spark,cloudera/spark,someorz/spark,apache-spark-on-k8s/spark,1haodian/spark,nilsgrabbert/spark,HyukjinKwon/spark,taroplus/spark,wangmiao1981/spark,michalsenkyr/spark,SnappyDataInc/spark,nlalevee/spark,bOOm-X/spark,kiszk/spark,zero323/spark,apache/spark,michalsenkyr/spark,bdrillard/spark,szhem/spark,BryanCutler/spark,debugger87/spark,ConeyLiu/spark,sachintyagi22/spark,darionyaphet/spark,srowen/spark,jianran/spark,goldmedal/spark,bOOm-X/spark,lyogavin/spark,lxsmnv/spark,poffuomo/spark,rezasafi/spark,skonto/spark,jianran/spark,bdrillard/spark,LantaoJin/spark,liyichao/spark,lyogavin/spark,aray/spark,ddna1021/spark,bdrillard/spark,SHASHANKB/spark,narahari92/spark,lvdongr/spark,cloud-fan/spark,eyalfa/spark,markhamstra/spark,ahnqirage/spark,ddna1021/spark,big-pegasus/spark,mdespriee/spark,skonto/spark,JerryLead/spark,apache-spark-on-k8s/spark,aokolnychyi/spark,big-pegasus/spark,xuanyuanking/spark,SHASHANKB/spark,eyalfa/spark,aokolnychyi/spark,Aegeaner/spark,tengpeng/spark,jkbradley/spark,szhem/spark,ptkool/spark,dongjoon-hyun/spark,yanboliang/spark,tengpeng/spark,hhbyyh/spark,sachintyagi22/spark,lxsmnv/spark,byakuinss/spark,WeichenXu123/spark,minixalpha/spark,mahak/spark,joseph-torres/spark,jrshust/spark,UndeadBaneGitHub/spark,kimoonkim/spark,lxsmnv/spark,ueshin/apache-spark,MLnick/spark,janewangfb/spark,kissmetrics/spark,facaiy/spark,janewangfb/spark,koeninger/spark,koeninger/spark,rikima/spark,michalsenkyr/spark,lvdongr/spark,esi-mineset/spark,kimoonkim/spark,esi-mineset/spark,byakuinss/spark,LantaoJin/spark,huang1900/spark,wangyum/spark,pronix/spark,loneknightpy/spark,jlopezmalla/spark,debugger87/spark,zero323/spark,rezasafi/spark,aosagie/spark,ueshin/apache-spark,setjet/spark,holdenk/spark,jlopezmalla/spark,witgo/spark,rikima/spark,mdespriee/spark,techaddict/spark,adrian-ionescu/apache-spark,SHASHANKB/spark,nilsgrabbert/spark,jrshust/spark,WindCanDie/spark,kevinyu98/spark,guoxiaolongzte/spark,shaneknapp/spark,facaiy/spark,nilsgrabbert/spark,ibm-research-ireland/sparkoscope,sachintyagi22/spark,rikima/spark,zuotingbing/spark,debugger87/spark,chuckchen/spark,wangyum/spark,taroplus/spark,darionyaphet/spark,ueshin/apache-spark,milliman/spark,ahnqirage/spark,shubhamchopra/spark,ptkool/spark,bdrillard/spark,goldmedal/spark,rjpower/spark,UndeadBaneGitHub/spark,map222/spark,jlopezmalla/spark,hvanhovell/spark,dotunolafunmiloye/spark,ajaysaini725/spark,ueshin/apache-spark,HyukjinKwon/spark,tejasapatil/spark,skonto/spark,sachintyagi22/spark,pronix/spark,zuotingbing/spark,icexelloss/spark,holdenk/spark,joseph-torres/spark,JoshRosen/spark,mahak/spark,patrick-nicholson/spark,vax11780/spark,ptkool/spark,icexelloss/spark,maropu/spark,hvanhovell/spark,LantaoJin/spark,ajaysaini725/spark,taroplus/spark,guoxiaolongzte/spark,LantaoJin/spark,nchammas/spark,hhbyyh/spark,BryanCutler/spark,xflin/spark,actuaryzhang/spark,tejasapatil/spark,apache-spark-on-k8s/spark,saltstar/spark,vinodkc/spark,cin/spark,sahilTakiar/spark,huang1900/spark,gioenn/xSpark,mike0sv/spark,stanzhai/spark,szhem/spark,kimoonkim/spark,stanzhai/spark,zzcclp/spark,WindCanDie/spark,dhruve/spark,gioenn/xSpark,1haodian/spark,ioana-delaney/spark,publicRoman/spark,caneGuy/spark,andrewor14/spark,huang1900/spark,kevinyu98/spark,markhamstra/spark,liutang123/spark,jkbradley/spark,mdespriee/spark,brad-kaiser/spark,mike0sv/spark,Panos-Bletsos/spark-cost-model-optimizer,liutang123/spark,liutang123/spark,yanboliang/spark,jrshust/spark,cin/spark,facaiy/spark,ajaysaini725/spark,pronix/spark,witgo/spark,aokolnychyi/spark,ueshin/apache-spark,saturday-shi/spark,sahilTakiar/spark,JerryLead/spark,taroplus/spark,maropu/spark,saturday-shi/spark,jlopezmalla/spark,dbtsai/spark,1haodian/spark,witgo/spark,szhem/spark,panfengfeng/spark,tejasapatil/spark,xuanyuanking/spark,zhouyejoe/spark,nlalevee/spark,esi-mineset/spark,zhouyejoe/spark,bravo-zhang/spark,ioana-delaney/spark,shaneknapp/spark,metamx/spark,HyukjinKwon/spark,poffuomo/spark,zuotingbing/spark,SHASHANKB/spark,MLnick/spark,sryza/spark,rezasafi/spark,vinodkc/spark,szhem/spark,maropu/spark,Aegeaner/spark,dhruve/spark,wgpshashank/spark,nlalevee/spark,narahari92/spark,cin/spark,saturday-shi/spark