*/
protected AbstractColumn buildExpressionColumn() {
ExpressionColumn column = new ExpressionColumn();
populateCommonAttributes(column);
int random = new Random().nextInt();
column.setColumnProperty(new ColumnProperty("expressionColumn" + random,CustomExpression.class.getName()));
column.setExpression(customExpression);
column.setExpressionToGroupBy(customExpressionToGroupBy);
// column.getFieldProperties().putAll(fieldProperties);
return column;
}