code: func StateFromParam(paramValue string) (*common.State, error) {
  
  	stateMap, err := objx.FromSignedBase64(paramValue, GetSecurityKey())
  
  	if err != nil {
  		return nil, err
  	}
  
  	return &common.State{Map: stateMap}, nil
  }
docs: // StateFromParam decodes the state parameter hash and turns it
  // into a usable State object.