code: def clear(self):
      self._canvas.create_rectangle(self.bbox, fill="white", width="0")
  
imports: from nltk.parse import MaltParser
  from nltk.sem.drt import DrsDrawer, DrtVariableExpression
  from nltk.sem.glue import DrtGlue
  from nltk.sem.logic import Variable
  from nltk.tag import RegexpTagger
  from nltk.util import in_idle
label_desc: Use image node_id 3 for calling the DrsWidget obj's underlying member method code with example usage: obj.clear() without return types