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: pkce.go
    path of file: ./repos/kubelogin/pkg/pkce
    
    the code of the file until where you have to start completion: // Package pkce provides generation of the PKCE parameters.
// See also 
    
func NewS256() (Params, error) {
	b, err := random32()
	if err != nil {
		return Plain, fmt.Errorf("could not generate a random: %w", err)
	}
	return computeS256(b), nil
}