code: def setLastLabel(
      self, text, line_color=None, fill_color=None, key_cls=None
  ):
      assert text
      self.shapes[-1].label = text
      if line_color:
          self.shapes[-1].line_color = line_color
  
      if fill_color:
          self.shapes[-1].fill_color = fill_color
  
      if key_cls:
          self.shapes[-1].key_cls = key_cls
  
      self.storeShapes()
  
      return self.shapes[-1]
  
imports: import copy
  from PyQt5.QtCore import Qt, pyqtSignal, QPointF, QPoint
  from PyQt5.QtGui import QPainter, QBrush, QColor, QPixmap
  from PyQt5.QtWidgets import QWidget, QMenu, QApplication
  from libs.shape import Shape
  from libs.utils import distance
label_desc: Use image node_id 46 for calling the Canvas obj's underlying member method code with example usage: obj.setLastLabel(text, line_color, fill_color, key_cls) and returns: self