code: public static Vector copy(Vector dest, Vector source) {
          for (int i = 0; i < source.length(); ++i)
              dest.set(i, source.getValue(i).doubleValue());
          return dest;
      }
docs: Copies all of the values from one {@code Vector} into another.  After the
  operation, all of the values in {@code dest} will be the same as that of
  {@code source}.  The legnth of {@code dest} must be as long as the length
  of {@code source}.  Once completed {@code dest} is returned.
  
  @param dest The {@code Vector} to copy values into.
  @param source The {@code Vector} to copy values from.
  
  @return {@code dest} after being copied from {@code source}.
  
  @throws IllegalArgumentException if the length of {@code dest} is less
  than that of {@code source}.