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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 on_enter_specimen(self, event):
 """ upon enter on the specimen box it makes that specimen the current specimen """

        new_specimen = self.specimens_box.GetValue()
        if new_specimen not in self.specimens:
            self.user_warning(
                "%s is not a valid specimen with measurement data, aborting" % (new_specimen))
            self.specimens_box.SetValue(self.s)
            return
        self.select_specimen(new_specimen)
        if self.ie_open:
            self.ie.change_selected(self.current_fit)
        self.update_selection()