stat/combin: Fix CombinationGenerator comment
It's confusing to say that Combination generates the next combination, when really it generates the current one with Next doing the advancing.
@@ -119,7 +119,7 @@ func (c *CombinationGenerator) Next() bool {
return true
}
-// Combination generates the next combination. If next is non-nil, it must have
+// Combination generates the current combination. If next is non-nil, it must have
// length k and the result will be stored in-place into combination. If combination
// is nil a new slice will be allocated and returned. If all of the combinations
// have already been constructed (Next() returns false), Combination will panic.
