docs: def txt(self, txt, h=None, at_x=None, to_x=None, change_style=None, change_size=None):
          """print string to defined (at_x) position
          to_x can apply only if at_x is None and if used then forces align='R'
          """
          h = h or self.height
          self._change_props(change_style, change_size)
          align = 'L'
          w = None
          if at_x is None:
              if to_x is not None:
                  align = 'R'
                  self.oPdf.set_x(0)
                  w = to_x
          else:
              self.oPdf.set_x(at_x)
          if w is None:
              w = self.oPdf.get_string_width(txt)
          self.oPdf.cell(w, h=h, txt=txt, align=align)