code: func (csp *CSP) GetKey(ski []byte) (k bccsp.Key, err error) {
  	k, err = csp.ks.GetKey(ski)
  	if err != nil {
  		return nil, errors.Wrapf(err, "Failed getting key for SKI [%v]", ski)
  	}
  
  	return
  }
docs: // GetKey returns the key this CSP associates to
  // the Subject Key Identifier ski.