public void GetNextOperatorTestSingleNot()
        {
            IOperator expectedResult    = new Not("hi");
            var       inputText         = "-hi";
            var       operatorExtractor = new OperatorExtractor(inputText);
            var       testResult        = operatorExtractor.GetNextOperator();

            Assert.Equal(expectedResult, testResult);
        }
        public void GetNextOperatorTestSingleAnd()
        {
            IOperator expectedResult    = new And("hi", invertedIndex.Object);
            var       inputText         = "hi";
            var       operatorExtractor = new OperatorExtractor(inputText);
            var       testResult        = operatorExtractor.GetNextOperator(invertedIndex.Object);

            Assert.Equal(expectedResult, testResult);
        }