Added test should_convert_ampersand() in test class UnicodeFileToHtmlTextConverterTest.
Created class TestingUnicodeFileToHtmlTextConverter which is the subclass of UnicodeFileToHtmlTextConverter.
Extracted method OpenTextReader() in class UnicodeFileToHtmlTextConverter which is going to be overridden by the subclass TestingUnicodeFileToHtmlTextConvert.
Changed the return type of method UnicodeFileToHtmlTextConverter.OpenTextReader() to be TextReader.
Overrode method OpenTextReader() in class TestingUnicodeFileToHtmlTextConverter.
Extracted method OpenStringReader() in class TestingUnicodeFileToHtmlTextConverter.
Introduced parameter strToBeConverted in method TestingUnicodeFileToHtmlTextConverter.OpenStringReader() to make the business logic clear.