mxHierarchicalLayout.prototype.findRoots=function(a,b){var c=[];if(null!=a&&null!=b){a=this.graph.model;var d=null,e=-1E5,f;for(f in b){var g=b[f];if(a.isVertex(g)&&this.graph.isCellVisible(g)){for(var k=this.getEdges(g),l=0,m=0,n=0;n<k.length;n++)this.getVisibleTerminal(k[n],!0)==g?l++:m++;0==m&&0<l&&c.push(g);k=l-m;k>e&&(e=k,d=g)}}0==c.length&&null!=d&&c.push(d)}return c};