joining static method

Collector<String, String?, String> joining([
  1. String? delimiter
])

Implementation

static Collector<String, String?, String> joining([String? delimiter]) {
  return _Collector<String, String?, String>(()=>null, (l,r){
    if(l==null) return r;
    return delimiter==null?l+r:l+delimiter+r;
  },(t)=>t==null?"":t);
}