old_contents: /**
   * @constructor
   * @param {string} coefficient
   */
  function NValue(coefficient) {
      this.coefficient = coefficient;
  }
  
  /**
   * @return {string}
   */
  NValue.prototype.toString = function toString() {
      var coef = this.coefficient;
      if (coef.asNumber) coef = coef.asNumber();
      if (coef === 1) {
          return 'n';
      } else if (!coef) {
          return '0';
      } else {
          return coef.toString() + 'n';
      }
  };
  
  /**
   * @return {string}
   */
  NValue.prototype.pretty = function pretty() {
      return this.toString();
  };
  
  /**
   * @return {NValue}
   */
  NValue.prototype.optimize = function optimize() {
      return this;
  };
  
  module.exports = NValue;
  
new_contents: /**
   * @constructor
   * @param {Number} coefficient
   */
  function NValue(coefficient) {
      this.coefficient = coefficient;
  }
  
  /**
   * @return {string}
   */
  NValue.prototype.toString = function toString() {
      var coef = this.coefficient;
      if (coef.asNumber) {
          coef = coef.asNumber();
      }
      if (coef === 1) {
          return 'n';
      } else if (!coef) {
          return '0';
      } else {
          return coef.toString() + 'n';
      }
  };
  
  /**
   * @return {string}
   */
  NValue.prototype.pretty = function pretty() {
      return this.toString();
  };
  
  /**
   * @return {NValue}
   */
  NValue.prototype.optimize = function optimize() {
      return this;
  };
  
  module.exports = NValue;
  
subject: Fix jsdoc in NValue