docs: function mergeMapTo(innerObservable, resultSelector, concurrent) {
  	    if (concurrent === void 0) { concurrent = Number.POSITIVE_INFINITY; }
  	    if (typeof resultSelector === 'number') {
  	        concurrent = resultSelector;
  	        resultSelector = null;
  	    }
  	    return this.lift(new MergeMapToOperator(innerObservable, resultSelector, concurrent));
  	}