code: def setVisibleColumns(self, visible):
          
          colnames = self.columns()
          for c, column in enumerate(colnames):
              self.setColumnHidden(c, column not in visible)
docs: Sets the list of visible columns for this widget.  This method will
          take any column in this tree's list NOT found within the inputed column
          list and hide them.
          
          :param      columns | [<str>, ..]