pdfmake-wrapper how to write a line with multiple style

Question

I'm trying this library which is a wrapper of pdfmake and I can't find how to make multiple styles inline, such as this example:

I've been struggling on this for a while.

user_11107672 · Answer

So I just found the answer to my question:

new Txt([
   new Txt('I\'ve been struggling').bold().end,
   ' on this for a',
   new Txt('while').italics().end
]).end