func (*JSONPb) ContentType() string {
	return "application/json"
}
ContentType implements gwruntime.Marshaler.
package grpcutil
import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"reflect"
	"github.com/gogo/protobuf/jsonpb"
	"github.com/gogo/protobuf/proto"
	gwruntime "github.com/grpc-ecosystem/grpc-gateway/runtime"
	"github.com/pkg/errors"
)
var _ gwruntime.Marshaler = (*JSONPb)(nil)
var typeProtoMessage = reflect.TypeOf((*proto.Message)(nil)).Elem()
type JSONPb jsonpb.Marshaler