toString() {
        const permissions = [];
        if (this.read) {
            permissions.push("r");
        }
        if (this.add) {
            permissions.push("a");
        }
        if (this.create) {
            permissions.push("c");
        }
        if (this.write) {
            permissions.push("w");
        }
        if (this.delete) {
            permissions.push("d");
        }
        if (this.deleteVersion) {
            permissions.push("x");
        }
        if (this.list) {
            permissions.push("l");
        }
        if (this.tag) {
            permissions.push("t");
        }
        if (this.move) {
            permissions.push("m");
        }
        if (this.execute) {
            permissions.push("e");
        }
        if (this.setImmutabilityPolicy) {
            permissions.push("i");
        }
        if (this.permanentDelete) {
            permissions.push("y");
        }
        if (this.filterByTags) {
            permissions.push("f");
        }
        return permissions.join("");
    }
Converts the given permissions to a string. Using this method will guarantee the permissions are in an
order accepted by the service.

The order of the characters should be as specified here to ensure correctness.
@see https://learn.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas