HashTable で includesKey を実装したい

前提・実現したいこと

HashTable の #includesKey
//key が含まれているなら true、ないなら false
を実装したいのですが、以下のコードであっているでしょうか？自信がありません。

HashTableEntry

Java
1public class HashTableEntry<K, V> {
2
3    private K key;
4    private V value;
5    private int hash;
6
7    public HashTableEntry(K key, V value) {
8        if (key == null)
9            throw new IllegalArgumentException("key cannot be null");
10
11        this.key = key;
12        this.value = value;
13        this.hash = key.hashCode();
14    }
15
16    public K getKey() {
17        return this.key;
18    }
19
20    public V getValue() {
21        return this.value;
22    }
23
24    public int getHashCode() {
25        return this.hash;
26    }
27
28    public String toString() {
29        return "{" + key + ": " + value + " (" + hash + ")}";
30    }
31
32}

HashTable

java
1import java.util.List;
2import java.util.LinkedList;
3import java.util.Arrays;
4
5
6public class HashTable<K, V> {
7
8    private Object[] entries;
9
10    private List<HashTableEntry<K, V>> bucket(int i) {
11        return (List<HashTableEntry<K, V>>)entries[i];
12    }
13
14    public HashTable(int numBuckets) {
15        if (numBuckets < 1)
16            throw new IllegalArgumentException("hash table must have at least one bucket");
17        this.entries = new Object[numBuckets];
18        for (int i = 0; i < numBuckets; i++)
19            this.entries[i] = new LinkedList<HashTableEntry<K, V>>();
20    }
21
22    public void put(K key, V value) {
23        HashTableEntry<K, V> e = new HashTableEntry<K, V>(key, value);
24        int h = e.getHashCode();
25        int b = Math.abs(h % this.entries.length);
26        bucket(b).add(e);
27    }
28
29    public V get(K key) {
30        int h = key.hashCode();
31        int b = Math.abs(h % this.entries.length);
32        for (HashTableEntry<K, V> e : bucket(b))
33            if (key.equals(e.getKey()))
34                return e.getValue();
35        return null;
36    }
37
38    public boolean includesKey(K key) {
39        for (HashTableEntry<K, V> e : bucket(this.entries.length))
40            if (key.equals(e.getKey()))
41                return true;
42        return false;
43    }
44
45}