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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def setImageItem(self, img):
 """Set an ImageItem to have its levels and LUT automatically controlled by this HistogramLUTItem. """

        self.imageItem = weakref.ref(img)
        img.sigImageChanged.connect(self.imageChanged)
        img.setLookupTable(self.getLookupTable)  ## send function pointer, not the result
        #self.gradientChanged()
        self.regionChanged()
        self.imageChanged(autoLevel=True)