code: public boolean sameState(final DoubleAdder other) {
  		return Double.compare(_sum, other._sum) == 0 &&
  			Double.compare(_simpleSum, other._simpleSum) == 0 &&
  			Double.compare(_compensation, other._compensation) == 0;
  	}
docs: Check if {@code this} and the {@code other} {@code DoubleAdder} maintain
  the same internal state.
  
  @param other the other object
  @return {@code true} if {@code this} and the {@code other} adder have
  the same state, {@code false otherwise}