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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 _linkToParent(self, feature, parentName):
 """ Link a feature with its children """

        parentParts = self.byFeatureName.get(parentName)
        if parentParts is None:
            raise GFF3Exception(
                "Parent feature does not exist: {}".format(parentName),
                self.fileName)
        # parent maybe disjoint
        for parentPart in parentParts:
            feature.parents.add(parentPart)
            parentPart.children.add(feature)