Inventory for Ultimate Character Controller can be better then this ??

guys if you can help me to make my game better and faster with out any error this code are fixed but i want to change it to better and teach me the new code please .

 namespace Opsive.UltimateCharacterController.Inventory
 {
     using Opsive.Shared.Inventory;
     using UnityEngine;
     using System.Collections.Generic;
 
     /// <summary>
     /// The ItemSetManager manages the ItemSets belonging to the character.
     /// </summary>
     public class ItemSetManager : ItemSetManagerBase
     {
         [Tooltip("A reference to the ItemCollection that the inventory is using.")]
         [SerializeField] protected ItemCollection m_ItemCollection;
 
         public ItemCollection ItemCollection { get { return m_ItemCollection; } set { var prevItemCollection = m_ItemCollection; 
                                                                                         m_ItemCollection = value; 
                                                                                         Initialize(prevItemCollection != m_ItemCollection); } }
 
         /// <summary>
         /// Initializes the ItemSetManager.
         /// </summary>
         /// <param name="force">Should the ItemSet be force initialized?</param>
         public override void Initialize(bool force)
         {
             if (m_Initialized && !force) {
                 return;
             }
             m_Initialized = true;
 
             if (m_ItemCollection == null) {
                 m_CategoryItemSets = null;
                 return;
             }
 
             // The ItemTypes get their categories from the ItemCollection.
             for (int i = 0; i < m_ItemCollection.ItemTypes.Length; ++i) {
                 m_ItemCollection.ItemTypes[i].Initialize(m_ItemCollection);
             }
 
             // Initialize the categories.
             if ((m_CategoryItemSets == null || m_CategoryItemSets.Length == 0)) {
                 if (m_ItemCollection.Categories.Length > 0) {
                     m_CategoryItemSets = new CategoryItemSet[m_ItemCollection.Categories.Length];
                 }
             } else if (m_CategoryItemSets.Length != m_ItemCollection.Categories.Length) {
                 System.Array.Resize(ref m_CategoryItemSets, m_ItemCollection.Categories.Length);
             }
             if (m_CategoryIndexMap == null) {
                 m_CategoryIndexMap = new Dictionary<IItemCategoryIdentifier, int>();
             } else {
                 m_CategoryIndexMap.Clear();
             }
             m_ActiveItemSetIndex = new int[m_CategoryItemSets.Length];
             m_NextItemSetIndex = new int[m_ActiveItemSetIndex.Length];
             for (int i = 0; i < m_CategoryItemSets.Length; ++i) {
                 m_ActiveItemSetIndex[i] = -1;
                 m_NextItemSetIndex[i] = -1;
                 if (m_CategoryItemSets[i] == null) {
                     m_CategoryItemSets[i] = new CategoryItemSet(m_ItemCollection.Categories[i].ID, m_ItemCollection.Categories[i].name, m_ItemCollection.Categories[i]);
                 } else {
                     m_CategoryItemSets[i].CategoryID = m_ItemCollection.Categories[i].ID;
                     m_CategoryItemSets[i].CategoryName = m_ItemCollection.Categories[i].name;
                     m_CategoryItemSets[i].ItemCategory = m_ItemCollection.Categories[i];
                 }
 
                 // Create a mapping between the category and index.
                 var category = m_ItemCollection.GetCategory(m_CategoryItemSets[i].CategoryID);
                 m_CategoryIndexMap.Add(category, i);
 
                 // The ItemSet must be initialized.
                 for (int j = 0; j < m_CategoryItemSets[i].ItemSetList.Count; ++j) {
                     m_CategoryItemSets[i].ItemSetList[j].Initialize(gameObject, this, m_CategoryItemSets[i].CategoryID, i, j);
                 }
             }
         }
     }
 }

your friend yusuf