@Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Grant other = (Grant) obj;
        if (grantee == null) {
            if (other.grantee != null)
                return false;
        } else if (!grantee.equals(other.grantee))
            return false;
        if (permission == null) {
            if (other.permission != null)
                return false;
        } else if (!permission.equals(other.permission))
            return false;
        return true;
    }