lib/utils/source-code-utils.js
function(lineNumber) {
        // Call getLines() just to ensure that this.sourceCodeTextLines property is set
        this.getLines();

        if (
            lineNumber && typeof lineNumber === "number" &&
			parseInt(lineNumber) === lineNumber &&	//ensure that argument is an INTEGER
			lineNumber >= 1 && lineNumber <= this.sourceCodeTextLines.length
        ) {
            return this.sourceCodeTextLines [lineNumber - 1];
        }

        throw new Error(`Line number ${lineNumber} invalid or out of bounds.`);
    }
function(lineNumber) {
        // Call getLines() just to ensure that this.sourceCodeTextLines property is set
        this.getLines();

        if (
            lineNumber && typeof lineNumber === "number" &&
			parseInt(lineNumber) === lineNumber &&	//ensure that argument is an INTEGER
			lineNumber >= 1 && lineNumber <= this.sourceCodeTextLines.length
        ) {
            return this.sourceCodeTextLines [lineNumber - 1];
        }

        throw new Error(`Line number ${lineNumber} invalid or out of bounds.`);
    }
Get the complete text on line lineNumber (excluding the EOL)
@param {int} lineNumber Line number whose text to get
@returns {String} code Source code text on the specified line