AppendCustomHeaderMiddleware appends custom headers.

AsGRPCError sets the gRPC status and error message according to the error type and metadata.

CustomMatcher is a callback function for gRPC-Gateway runtime.WithIncomingHeaderMatcher.

ErrorHandler is a callback function for gRPC-Gateway runtime.WithErrorHandler.

HTTPResponseModifier is a callback function for gRPC-Gateway runtime.WithForwardResponseOption.

RecoveryInterceptorOpt - panic handler.

StreamAppendMetadataInterceptor - append metadata for stream.

UnaryAppendMetadataAndErrorCodeInterceptor - append metadata for unary.