code: function freezeOptions(options) {
      // Freeze each property objects
      Object.getOwnPropertyNames(options).forEach(optionName => {
          if (optionName === 'valuesToStrings') {
              const vsProps = Object.getOwnPropertyNames(options.valuesToStrings);
              vsProps.forEach(valuesToStringObjectName => {
                  if (!AutoNumericHelper.isIE11() && options.valuesToStrings[valuesToStringObjectName] !== null) {
                      Object.freeze(options.valuesToStrings[valuesToStringObjectName]);
                  }
              });
          } else if (optionName !== 'styleRules') {
              if (!AutoNumericHelper.isIE11() && options[optionName] !== null) {
                  Object.freeze(options[optionName]);
              }
          }
      });
  
      // Then freeze the options object globally
      return Object.freeze(options);
  }
docs: Simple function that will semi-deep freeze the `AutoNumeric.options` object.
  By 'semi' it means the nested objects in the `styleRules` option are not frozen.
  The ones in the `valuesToStrings` are though, since they are much more simple.
  
  @param {object} options
  @returns {ReadonlyArray<any>}