Finished TODO: should convert greater than and less than.
Removed duplicate code in the test class.
Finisehd TODO: should add a line break for a new line.
Finished TODO: Depending on the file system violates the Dependency Inversion Principle and Open-Closed Principle. Finished TODO: Make the method convertToHtml() working for not only a file but also a string.
Working on TODO: Depending on the third party library violates the Dependency Inversion Principle and Open-Closed Principle. Wrote intention code in the test class to inject an ApacheCommonsEscaper implementing the interface HtmlEscaper.
Created interface HtmlEscaper.
Created class ApacheCommonsEscaper which implements the interface HtmlEscaper.
Created constructor UnicodeFileToHtmlTextConverter(ConvertingSource, HtmlEscaper) and made the other two constructors assign a value to the field htmlEscaper.
Wrote the intention code in method UnicodeFileToHtmlTextConverter.convertToHtml() to make this class depend on the abstraction -- HtmlEscaper.
Added method escape() into the interface HtmlEscaper.
Implemented method escape() in class ApacheCommonsEscaper.
Finished TODO: Depending on the third party library violates the Dependency Inversion Principle and Open-Closed Principle.