code: private final boolean get(int i) {
  
          boolean in_the_set = false;
          int j = (i >> SHIFT_PER_WORD); // wordIndex(i)
          // an optimization here, ... a quick test to see
          // if this integer is beyond any of the words in use
          if(j < firstWordNotUsed)
              in_the_set = (array_of_bits[j] & 
                            (1 << (i & LOW_ORDER_BITMASK))
              ) != 0;  // 0L for 64 bit words
          return in_the_set;
      }
docs: Return true if the integer (character)is in the set of integers.
  
  This implementation uses an array of integers with 32 bits per
  integer.  If a bit is set to 1 the corresponding integer is
  in the set of integers.
  
  @param i an integer that is tested to see if it is the
  set of integers, or not.