code: private void resize()
      {
          Entry[] oldTab = table;
          int oldLen = oldTab.length;
          int newLen = oldLen * 2;
          Entry[] newTab = new Entry[newLen];
          int count = 0;
  
          for (int j = 0; j < oldLen; ++j)
          {
              Entry e = oldTab[j];
              if (e != null)
              {
                  int h = e.key.hashCode & (newLen - 1);
                  while (newTab[h] != null)
                      h = nextIndex(h, newLen);
                  newTab[h] = e;
                  count++;
              }
          }
  
          setThreshold(newLen);
          size = count;
          table = newTab;
      }
docs: Double the capacity of the table.