unity how to access the parameter from animator code example

Example: how to set an animator parameter through the animator unity

//click the add behaviour button on a state in the animator controller
 	//and add a script. Just put the name of the bool in the inspector
 public class AnimatorResetBoolAtEnd : StateMachineBehaviour {
 
         [SerializeField]
         private string booleanVariableName;
 
   
         // OnStateExit is called when a transition ends and the state 
         //machine finishes evaluating this state
         override public void OnStateExit(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
         {
             animator.SetBool(booleanVariableName, false);
         }
 
        
     }