code: def moveVertexBy(self, i, offset):
      self.points[i] = self.points[i] + offset
  
imports: import math
  import sys
  from PyQt5.QtCore import QPointF
  from PyQt5.QtGui import QColor, QPen, QPainterPath, QFont
  from libs.utils import distance
label_desc: Use image node_id 18 for calling the Shape obj's underlying member method code with example usage: obj.moveVertexBy(i, offset) without return types