}
protected DynamicOperand score( String... tableNames ) {
DynamicOperand operand = null;
for (String tableName : tableNames) {
DynamicOperand right = new FullTextSearchScore(new SelectorName(tableName));
if (operand == null) operand = right;
else operand = new ArithmeticOperand(operand, ArithmeticOperator.ADD, right);
}
assert operand != null;
return operand;