Integer[] cell = l.toArray(new Integer[0]);
int[] c = new int[cell.length];
for (int k = 0; k < c.length; k++) {
c[k] = cell[k].intValue();
}
if (neighborhood.containsCell(c)) {
addProblemToken(CAProblemToken.VALUE_OUT_OF_RANGE,
(LEFT_BRACE4 != null ? LEFT_BRACE4.getTokenIndex() : 0),
"Cell already in neighborhood.");
} else {
neighborhood.addCell(c);