class_docstr: An icon place holder for lazy loading of QIcons
  
  The icon must reside in the icons folder and the path refers to the full
  name including suffix of the icon file, e.g.:
  
      tiny = GraphIcon("tiny.png")
  
  Icons can be later retrieved via the function `getGraphIcon` and providing
  the name:
  
      tiny = getGraphIcon("tiny")
code: def _build_qicon(self):
      icon = QtGui.QIcon(op.join(op.dirname(__file__), self._path))
      name = self._path.split(".")[0]
      _ICON_REGISTRY[name] = icon
      self._icon = icon
  
file_path: pyqtgraph/pyqtgraph/icons/__init__.py
imports: import os.path
  import warnings
  from ..Qt import QtGui, QtWidgets
label_desc: Use image node_id 2 for calling the GraphIcon obj's underlying member method code with example usage: obj._build_qicon() without return types