diff --git a/NEXT b/NEXT
new file mode 100644
index 0000000..0d5e890
--- /dev/null
+++ b/NEXT
@@ -0,0 +1,4 @@
+- Panic in verification that 2*eps is less than bucket width.
+  Make sure the "if" equality is correct.
+
+- Make sure hash contains ":" between bucket numbers. Or the analogy to ":".
\ No newline at end of file
diff --git a/hashes.go b/hashes.go
index 1ba82d7..a313277 100644
--- a/hashes.go
+++ b/hashes.go
@@ -6,10 +6,12 @@ import (
 	"hash/fnv"
 )
 
+// Hash64 can be any function of this kind.
 type Hash64 func(buckets []int) uint64
 
-// Fnva64 returns a FVN-1a hash for a slice of bucket numbers.
-func Fnva64(buckets []int) uint64 {
+// Default is the default Hash64 function for this package.
+// It returns a FVN-1a hash for a slice of bucket numbers.
+func Default(buckets []int) uint64 {
 	var b bytes.Buffer
 	gob.NewEncoder(&b).Encode(buckets)
 	hash := fnv.New64a()
diff --git a/hashes_test.go b/hashes_test.go
index 946744d..ce89755 100644
--- a/hashes_test.go
+++ b/hashes_test.go
@@ -5,9 +5,9 @@ import (
 	"testing"
 )
 
-func TestFnva64(t *testing.T) {
+func TestDefault(t *testing.T) {
 	buckets := []int{5, 59, 255, 9, 7, 12, 22, 31}
-	hash := Fnva64(buckets)
+	hash := Default(buckets)
 	want := uint64(13992349377752315208)
 	if hash != want {
 		t.Errorf(`Got %v, want %v`, hash, want)
@@ -20,7 +20,7 @@ func TestHashes64(t *testing.T) {
 		{1, 0, 7, 3, 0, 0, 9},
 		{0, 0, 8, 3, 0, 0, 9},
 		{1, 0, 8, 3, 0, 0, 9}}
-	hs := Hashes64(tree, Fnva64)
+	hs := Hashes64(tree, Default)
 	want := []uint64{
 		14647827280143437043,
 		17530493565529410009,