func Open(name string) (*Index, error) {
	if !validIndexNameOrDocID(name) {
		return nil, fmt.Errorf("search: invalid index name %q", name)
	}
	return &Index{
		spec: pb.IndexSpec{
			Name: &name,
		},
	}, nil
}
func Open(name string) (*Index, error) {
	if !validIndexNameOrDocID(name) {
		return nil, fmt.Errorf("search: invalid index name %q", name)
	}
	return &Index{
		spec: pb.IndexSpec{
			Name: &name,
		},
	}, nil
}
// Open opens the index with the given name. The index is created if it does
// not already exist.
//
// The name is a human-readable ASCII string. It must contain no whitespace
// characters and not start with "!".