Method Concurrent.fold()
- Method fold
 Futurefold(array(Future)futures,mixedinitial,function(mixed,mixed,mixed... :mixed)fun,mixed...extra)- Description
 Return a Future that represents the accumulated results of applying
funto the results of thefuturesin turn.- Parameter 
initial Initial value of the accumulator.
- Parameter 
fun Function to apply. The first argument is the result of one of the
futures, the second the current accumulated value, and any further fromextra.- Note
 If
funthrows an error it will fail the Future.- Note
 funmay be called in any order, and will be called once for every Future infutures, unless one of calls fails in which case no further calls will be performed.