code: def buildGradientSubMenu(self):
      source = "preset-gradient"
      names = list(Gradients.keys())
      self.buildSubMenu(names, source, sort=False)
  
imports: import importlib.util
  import re
  import numpy
  from ..None import colormap
  from ..None import functions
  from ..graphicsItems.GradientPresets import Gradients
  from ..Qt import QtCore, QtGui, QtWidgets
label_desc: Use image node_id 2 for calling the ColorMapMenu obj's underlying member method code with example usage: obj.buildGradientSubMenu() without return types