class_docstr: Used for displaying a button within the tree.
  
  ``sigActivated(self)`` is emitted when the button is clicked.
  
  Parameters
  ----------
  icon: str
      Icon to display in the button. Can be any argument accepted
      by :class:`QIcon <QtGui.QIcon>`.
  shortcut: str
      Key sequence to use as a shortcut for the button. Note that this shortcut is
      associated with spawned parameters, i.e. the shortcut will only work when this
      parameter has an item in a tree that is visible. Can be set to any string
      accepted by :class:`QKeySequence <QtGui.QKeySequence>`.
code: def activate(self):
      self.sigActivated.emit(self)
      self.emitStateChanged("activated", None)
  
file_path: pyqtgraph/pyqtgraph/parametertree/parameterTypes/action.py
imports: from ...Qt import QtCore, QtWidgets, QtGui
  from ..Parameter import Parameter
  from ..ParameterItem import ParameterItem
label_desc: Use image node_id 1 for calling the ActionParameter obj's underlying member method code with example usage: obj.activate() without return types