Null Reference When Calling OnTriggerEnter?

Hello all,

long story short, I am creating an object pooling system and in my script (see below), PickAxeTestManager, I am getting ERROR CS1501 "No overload for method OnTriggerEnter takes 0 arguments" on line 22.

 using UnityEngine;
 using System.Collections;
 
 public class PickAxeTestManager : MonoBehaviour {
 
     public GameObject PickAxeprefab;
 
     void Start ()
     {
         PickAxePoolManager.instance.CreatePool (PickAxeprefab, 2); //CreatePool is a method in PickAxePoolManager
     }
 
 
     void Update () 
     {
 
         if (Input.GetKeyDown (KeyCode.A)) 
         {
             PickAxePoolManager.instance.ReuseObject(PickAxeprefab, Vector3.zero, Quaternion.identity); //ReuseObject is also a method in PickAxePoolManager 
         }
 
         if (ResetByWall.instance.OnTriggerEnter()) //ERROR CS1501 is here. "No overload for method OnTriggerEnter takes 0 arguments". 
         {
             PickAxePoolManager.instance.ReuseObject(PickAxeprefab, Vector3.zero, Quaternion.identity); // Same here...        
         }
     }
 }

Here is my ResetByWall script (below), I have this script because when my PickAxe hits the "South Wall", I want it to go back into the pooling system (but for now, I am just "Destroying" it lol until I get the logic figured out).

 using UnityEngine;
 using System.Collections;
 
 public class ResetByWall : MonoBehaviour {
 
     public bool collided;
 
     //NOTE:
     //Singleton Pattern from lines 12 to 25 //
     // ************************************
 
     static ResetByWall _instance; // Reference to the Reset By Wall script
     
     public static ResetByWall instance    // This is the accessor
     {
         get 
         {
             if(_instance == null)    // Check to see if _instance is null
             {
                 _instance = FindObjectOfType<ResetByWall>(); //Find the instance in the Reset By Wall script in the currently active scene
             }
             
             return _instance;
         }
     }
 
     //public GameObject prefab;
 
     public void OnTriggerEnter(Collider other) {
 
         collided = true;
 
         if (other.gameObject.tag == "Pick Axe_PoolerTest") //I tagged the prefab as "Pick Axe_PoolerTest"
         {
             Debug.Log("Pick Axe entered the trigger!");
 
             Destroy(other.gameObject);
 
         }
 
     }
 }

My question is: can the OnTriggerEnter take an argument that is not of "type collider" so that I can rid of this "Null Reference" ? I did a lot of research before I asked this question and I could not find anything!

Also, here is my PickAxePoolManager script below (this is the main backbone of everything I am working on right now), but I am sure the only parts of this script you MIGHT even need to look at are the methods, CreatePool and ReuseObject.

  using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class PickAxePoolManager : MonoBehaviour {
     
     Dictionary<int,Queue<GameObject>> poolDictionary = new Dictionary<int,Queue<GameObject>>();
     
     //NOTE: 
     //Singleton Pattern used from lines 12 to 25
 
     static PickAxePoolManager _instance; // Reference to the Pool Manager script
     
     public static PickAxePoolManager instance    // This is the accessor
     {
         get 
         {
             if(_instance == null)    // Check to see if _instance is null
             {
                 _instance = FindObjectOfType<PickAxePoolManager>(); //Find the instance in the Pool Manager script in the currently active scene
             }
             
             return _instance;
         }
     }
     
     /// <summary>
     /// Creates the pool.
     /// </summary>
     /// <param name="prefab">Prefab.</param>
     /// <param name="poolSize">Pool size.</param>
     
     public void CreatePool(GameObject prefab, int poolSize)
     {
         int poolKey = prefab.GetInstanceID ();     // Unique integer for every GameObject
         
         if (!poolDictionary.ContainsKey (poolKey))     //Make sure poolKey is not already in the Dictionary, 
             //if it's not then we can create the pool 
         {
             poolDictionary.Add(poolKey, new Queue<GameObject>());
             
             for (int i = 0; i < poolSize; i++)     //Instantiate the prefabs as dictated by the "poolSize" integer
             {
                 GameObject newObject = Instantiate (prefab) as GameObject;     //Instantiate as a GameObject
                 newObject.SetActive(false);     // Don't want it to be visible in the scene yet
                 poolDictionary [poolKey].Enqueue(newObject);    // Add it to our Pool
             }
         }
     }
     
     /// <summary>
     /// Reuses the object in our pool.
     /// </summary>
     /// <param name="prefab">Prefab.</param>
     /// <param name="position">Position.</param>
     /// <param name="rotation">Rotation.</param>
     
     public void ReuseObject (GameObject prefab, Vector3 position, Quaternion rotation)
     {
         int poolKey = prefab.GetInstanceID ();    // Get our pool key once again
         
         if (poolDictionary.ContainsKey (poolKey)) // Quick check to make sure our pool dictionary contains the pool key
         {
             GameObject objectToReuse = poolDictionary[poolKey].Dequeue(); //Get the next object in the pool
             poolDictionary[poolKey].Enqueue(objectToReuse);    // Add the object back onto the end of the queue so it can be reused later
             
             objectToReuse.SetActive(true);    //Make sure the object was not disabled
             
             objectToReuse.transform.position = position; // set position to applied values
             objectToReuse.transform.rotation = rotation; // set rotation to applied values
         }    
     }
 }

If you need more details, just let me know. Thank you! :)