code: def setText(self, text):
          
          if self.text() == text:
              return
          self.touch()
          maxSize = len(self.text()) + 1
          self.device.press('KEYCODE_DEL', adbclient.DOWN_AND_UP, repeat=maxSize)
          self.device.press('KEYCODE_FORWARD_DEL', adbclient.DOWN_AND_UP, repeat=maxSize)
          self.type(text, alreadyTouched=True)
docs: This function makes sure that any previously entered text is deleted before
          setting the value of the field.