code: def _appendGlyph(self, other, offset=None):
          
          other = other.copy()
          if offset != (0, 0):
              other.moveBy(offset)
          for contour in other.contours:
              self.appendContour(contour)
          for component in other.components:
              self.appendComponent(component=component)
          for anchor in other.anchors:
              self.appendAnchor(anchor=anchor)
          for guideline in other.guidelines:
              self.appendGuideline(guideline=guideline)
docs: Subclasses may override this method.