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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 readInstance(self, key, makeGlyphs=True, makeKerning=True, makeInfo=True):
 """ Read a single instance element. key: an (attribute, value) tuple used to find the requested instance. :: <instance familyname="SuperFamily" filename="OutputNameInstance1.ufo" location="location-token-aaa" stylename="Regular"> """

        attrib, value = key
        for instanceElement in self.root.findall('.instances/instance'):
            if instanceElement.attrib.get(attrib) == value:
                self._readSingleInstanceElement(instanceElement, makeGlyphs=makeGlyphs, makeKerning=makeKerning, makeInfo=makeInfo)
                return
        raise MutatorError("No instance found with key: (%s, %s)." % key)