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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 insert_concurrent_execution_histories(self, parent, concurrent_execution_histories):
 """Adds the child execution histories of a concurrency state. :param Gtk.TreeItem parent: the parent to add the next history item to :param list[ExecutionHistory] concurrent_execution_histories: a list of all child execution histories :return: """

        for execution_history in concurrent_execution_histories:
            if len(execution_history) >= 1:
                first_history_item = execution_history[0]
                # this is just a dummy item to have an extra parent for each branch
                # gives better overview in case that one of the child state is a simple execution state
                tree_item = self.insert_history_item(parent, first_history_item, "Concurrency Branch", dummy=True)
                self.insert_execution_history(tree_item, execution_history)