code: func (h *HashMap) Delete(k T) {
  	hash := h.hash(k)
  	var prev *hashEntry
  	for entry := h.table[hash]; entry != nil; entry = entry.next {
  		if h.eq(entry.k, k) {
  			if prev != nil {
  				prev.next = entry.next
  			} else {
  				h.table[hash] = entry.next
  			}
  			h.size--
  			return
  		}
  		prev = entry
  	}
  }
docs: // Delete removes the the key k.