remove dead code
diff --git a/metadata/metadata.go b/metadata/metadata.go
index 9e39b1a..52070db 100644
--- a/metadata/metadata.go
+++ b/metadata/metadata.go
@@ -46,17 +46,6 @@
binHdrSuffix = "-bin"
)
-// grpc-http2 requires ASCII header key and value (more detail can be found in
-// "Requests" subsection in go/grpc-http2).
-func isASCII(s string) bool {
- for _, c := range s {
- if c > 127 {
- return false
- }
- }
- return true
-}
-
// encodeKeyValue encodes key and value qualified for transmission via gRPC.
// Transmitting binary headers violates HTTP/2 spec.
// TODO(zhaoq): Maybe check if k is ASCII also.
