i have to calculate the average of a Infinite Sequence using Stream API

Input:

```
Stream<Double> s = a,b,c,d ...
int interval = 3

```

Expected Result:

```
Stream<Double> result = avg(a,b,c), avg(d,e,f), ....

```

the result can be also an Iterator, or any other type
as long as it mantains the structure of an infinite list

of course what i written is pseudo code and doesnt run