code: def updateDefaultBtn(self):
      # Override since a readonly label should still allow reverting to default
      ## enable/disable default btn
      self.defaultBtn.setEnabled(
          not self.param.valueIsDefault() and self.param.opts["enabled"]
      )
  
      # hide / show
      self.defaultBtn.setVisible(self.param.hasDefault())
  
file_path: pyqtgraph/pyqtgraph/parametertree/parameterTypes/file.py
imports: import os
  import re
  from ...Qt import QtCore, QtGui, QtWidgets
  from ..Parameter import Parameter
  from .str import StrParameterItem
label_desc: Use image node_id 7 for calling the FileParameterItem obj's underlying member method code with example usage: obj.updateDefaultBtn() without return types