for (int i = 0; i < props.length; i++) {
Object firstRowValue = getValueAt(0, i);
if (firstRowValue instanceof String) {
for (int j = 0; j < nrows; j++) {
String stringValue = (String) getValueAt(j, i);
result += sizeEstimator.sizeOfString(stringValue);
}
} else {
int singleValueSize = sizeEstimator.sizeOf(firstRowValue);
result += nrows * singleValueSize;
}