static isBeforeOrEqual(a, b) {
        if (a.lineNumber < b.lineNumber) {
            return true;
        }
        if (b.lineNumber < a.lineNumber) {
            return false;
        }
        return a.column <= b.column;
    }
Test if position `a` is before position `b`.
If the two positions are equal, the result will be true.