joinLists function
Joins all parameters to a single list.
Implementation
List joinLists(List? l1,
[List? l2,
List? l3,
List? l4,
List? l5,
List? l6,
List? l7,
List? l8,
List? l9]) {
var l = [];
if (l1 != null) l.addAll(l1);
if (l2 != null) l.addAll(l2);
if (l3 != null) l.addAll(l3);
if (l4 != null) l.addAll(l4);
if (l5 != null) l.addAll(l5);
if (l6 != null) l.addAll(l6);
if (l7 != null) l.addAll(l7);
if (l8 != null) l.addAll(l8);
if (l9 != null) l.addAll(l9);
return l;
}