You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: grpc.go
    path of file: ./repos/podman/vendor/github.com/containerd/errdefs
    
    the code of the file until where you have to start completion: /*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under t
    
func FromGRPC(err error) error {
	if err == nil {
		return nil
	}

	var cls error // divide these into error classes, becomes the cause

	switch code(err) {
	case codes.InvalidArgument:
		cls = ErrInvalidArgument
	case codes.AlreadyExists:
		cls = ErrAlreadyExists
	case codes.NotFound:
		cls = ErrNotFound
	case codes.Unavailable:
		cls = ErrUnavailable
	case codes.FailedPrecondition:
		cls = ErrFailedPrecondition
	case codes.Unimplemented:
		cls = ErrNotImplemented
	case codes.Canceled:
		cls = context.Canceled
	case codes.DeadlineExceeded:
		cls = context.DeadlineExceeded
	default:
		cls = ErrUnknown
	}

	msg := rebaseMessage(cls, err)
	if msg != "" {
		err = fmt.Errorf("%s: %w", msg, cls)
	} else {
		err = cls
	}

	return err
}