http://kelvinlawrence.net/book/Gremlin-Graph-Guide.html
[abq,kabq,atl,katl,bkg,kbbg,bna,kbna,bos,kbos,bwi,kbwi,cle,kcle,clt,kclt,cun,mmun,cvg,kcvg,dal,kdal,dca,kdca,den,kden,dfw,kdfw,dtw,kdtw,elp,kelp,ewr,kewr,fll,kfll,fra,eddf,gdl,mmgl,hou,khou,hrl,khrl,iad,kiad,iah,kiah,ind,kind,jfk,kjfk,las,klas,lax,klax,lbb,klbb,lgb,klgb,lhr,egll,mci,kmci,mco,kmco,mdw...