includes

includes(value: MemberType): Boolean;

The includes method of the Set class returns true if the object specified in the value parameter is contained in the set; for example:

isEmployee(emp: Employee): Boolean;
// returns true if an emp is below self in the organization hierarchy
vars
    child : Employee;
    bool  : Boolean;
begin
    if myEmployees.size <> 0 then
        if myEmployees.includes(emp) then
            bool := true;
        else
            foreach child in myEmployees do
                if child.isEmployee(emp) = true then
                    bool := true;
                    break;
                endif;
            endforeach;
        endif;
    endif;
    bool := false;
    return bool;
end;

if not goodCustomers.includes(cust) then
    goodCustomers.add(cust);
endif;