code: func (h *HashMap) Iter(iter func(T, T) bool) bool {
  	for _, entry := range h.table {
  		for ; entry != nil; entry = entry.next {
  			if iter(entry.k, entry.v) {
  				return true
  			}
  		}
  	}
  	return false
  }
docs: // Iter invokes the iter function for each element in the HashMap.
  // If the iter function returns true, iteration stops and the return value is true.
  // If the iter function never returns true, iteration proceeds through all elements
  // and the return value is false.