TextReader documentation

Is there any documentation for the TextReader object? Trying to find out what properties and methods can be used other than those shown in example code.

Hello,

openTextReader() and openTextWriter() are javascript function. They are not function proper to Connect. Please look at the attached documentation.

TextReader

And yet the doco you give me is for java. So that suggests that TextReader is a java object that Objectif Line have implemented somehow in their javascript engine for data mapper.