code: public static final Assignment fromUnsortedArrays(int[] vars, Object[] values) {
      ArrayUtils.sortKeyValuePairs(vars, new Object[][] {values}, 0, vars.length);
      return fromSortedArrays(vars, values);
    }
docs: Creates an {@code Assignment} mapping each variable in {@code vars} to the value
  at the corresponding index of {@code values}. {@code vars} does not need
  to be sorted in any order. This method does not copy {@code vars} or
  {@code values} and may modify either array; the caller should not read
  or modify either of these arrays after invoking this method.
  
  @param vars
  @param values
  @return