add Printable example to docs

bindings/go/src/fdb/fdb.go

@@ -380,8 +380,15 @@ func (k Key) FDBKey() Key {
 
 // String describes the key as a hexadecimal encoded string.
 func (k Key) String() string {
+	return Printable(k)
+}
+
+// Printable returns a human readable version of a byte array. The bytes that correspond with
+// ASCII printable characters [32-127) are passed through. Other bytes are
+// replaced with \x followed by a two character zero-padded hex code for byte.
+func Printable(d []byte) string {
 	var sb strings.Builder
-	for _, b := range k {
+	for _, b := range d {
 		if b >= 32 && b < 127 && b != '\\' {
 			sb.WriteByte(b)
 			continue

bindings/go/src/fdb/fdb_test.go

@@ -268,8 +268,8 @@ func TestKeyToString(t *testing.T) {
 		key    fdb.Key
 		expect string
 	}{
-		{fdb.Key("plain-text"), "plain-text"},
 		{fdb.Key([]byte{0}), "\\x00"},
+		{fdb.Key("plain-text"), "plain-text"},
 		{fdb.Key("\xbdascii☻☺"), "\\xbdascii\\xe2\\x98\\xbb\\xe2\\x98\\xba"},
 	}
 
@@ -279,3 +279,8 @@ func TestKeyToString(t *testing.T) {
 		}
 	}
 }
+
+func ExamplePrintable() {
+	fmt.Println(fdb.Printable([]byte{0, 1, 2, 'a', 'b', 'c', '1', '2', '3', '!', '?', 255}))
+	// Output: \x00\x01\x02abc123!?\xff
+}