Simple HashSet implementation

Set.java

import java.util.Objects;
public class Set {
    private final Object[][] elements;
    private int size = 0;
    public Set(int capacity) {
        elements = new Object[capacity][];
    }

    public Set() {
        this(32);
    }

    public boolean isEmpty() {
        return size == 0;
    }

    public void add(Object element) {
        final int index = indexOf(element);
        if (elements[index] == null) {
            elements[index] = new Object[] { element };
        } else {
            final Object[] existingChain = elements[index];
            if (indexInChain(existingChain, element) > -1) {
                return;
            }
            final Object[] newChain = new Object[existingChain.length + 1];
            System.arraycopy(existingChain, 0, newChain, 0, existingChain.length);
            newChain[existingChain.length] = element;
            elements[index] = newChain;
        }
        size++;
    }
    public void remove(Object element) {
        final int index = indexOf(element);
        if (elements[index] != null) {
            final Object[] chain = elements[index];
            final int indexInChain = indexInChain(chain, element);
            if (indexInChain == -1) {
                return;
            }
            final Object[] newChain = new Object[chain.length - 1];
            System.arraycopy(chain, 0, newChain, 0, indexInChain);
            System.arraycopy(chain, indexInChain + 1, newChain, indexInChain, chain.length - indexInChain - 1);
            elements[index] = newChain;
            size--;
        }
    }

    public int size() {
        return size;
    }

    public boolean contains(Object element) {
        final int index = indexOf(element);
        if (elements[index] != null) {
            final Object[] chain = elements[index];
            return indexInChain(chain, element) > -1;
        }
        return false;
    }

    static int indexInChain(Object[] chain, Object element) {
        for (int i = 0; i < chain.length; i++) {
            if (Objects.equals(chain[i], element)) {
                return i;
            }
        }
        return -1;
    }

    int indexOf(Object element) {
        return element.hashCode() % elements.length;
    }
}