/**
   * Fills all pairs satisfying a given condition into the specified lists. Fills into the lists,
   * starting at index 0. After this call returns the specified lists both have a new size, the
   * number of pairs satisfying the condition. Iteration order is guaranteed to be <i>identical</i>
   * to the order used by method {@link #forEachKey(DoubleProcedure)}.
   *
   * <p><b>Example:</b> <br>
   *
   * <pre>
   * DoubleIntProcedure condition = new DoubleIntProcedure() { // match even values only
   * public boolean apply(double key, int value) { return value%2==0; }
   * }
   * keys = (8,7,6), values = (1,2,2) --> keyList = (6,8), valueList = (2,1)</tt>
   * </pre>
   *
   * @param condition the condition to be matched. Takes the current key as first and the current
   *     value as second argument.
   * @param keyList the list to be filled with keys, can have any size.
   * @param valueList the list to be filled with values, can have any size.
   */
  public void pairsMatching(
      final DoubleIntProcedure condition,
      final DoubleArrayList keyList,
      final IntArrayList valueList) {
    keyList.clear();
    valueList.clear();

    for (int i = table.length; i-- > 0; ) {
      if (state[i] == FULL && condition.apply(table[i], values[i])) {
        keyList.add(table[i]);
        valueList.add(values[i]);
      }
    }
  }
 /**
  * Applies a procedure to each (key,value) pair of the receiver, if any. Iteration order is
  * guaranteed to be <i>identical</i> to the order used by method {@link
  * #forEachKey(DoubleProcedure)}.
  *
  * @param procedure the procedure to be applied. Stops iteration if the procedure returns
  *     <tt>false</tt>, otherwise continues.
  * @return <tt>false</tt> if the procedure stopped before all keys where iterated over,
  *     <tt>true</tt> otherwise.
  */
 public boolean forEachPair(final DoubleIntProcedure procedure) {
   for (int i = table.length; i-- > 0; ) {
     if (state[i] == FULL) if (!procedure.apply(table[i], values[i])) return false;
   }
   return true;
 }