in indigo.js [1102:1107]
IndigoObject.prototype.grossFormula = function() {
this.d._setSessionId();
let gfid = this.d._checkResult(this.d._lib.indigoGrossFormula(this.id));
let gf = new IndigoObject(this.d, gfid);
return this.d._checkResultString(this.d._lib.indigoToString(gf.id));
};