@Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        } else if (obj instanceof JoinFlag) {
            return ((JoinFlag) obj).flag.equals(flag);
        } else {
            return false;
        }
    }
Create a new instance using the given flag and position

@param flag flag in Expression form
@param position position of the flag in the join
querydsl-core/src/main/java/com/querydsl/core/JoinFlag.java