code: public boolean contains(final double k) {
  		long longKey = Double.doubleToLongBits(k);
  		if (longKey == 0L) {
  			return this.containsZero;
  		} else {
  			double[] key = this.key;
  			long curr;
  			int pos;
  			if ((curr = Double.doubleToLongBits(key[pos = (int) MurmurHashUtil.fmix(longKey) & this.mask])) == 0L) {
  				return false;
  			} else if (longKey == curr) {
  				return true;
  			} else {
  				while ((curr = Double.doubleToLongBits(key[pos = pos + 1 & this.mask])) != 0L) {
  					if (longKey == curr) {
  						return true;
  					}
  				}
  
  				return false;
  			}
  		}
  	}
docs: See {@link Double#equals(Object)}.