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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 get_form_prefix(self, step=None, form=None):
 """ Returns the prefix which will be used when calling the actual form for the given step. `step` contains the step-name, `form` the form which will be called with the returned prefix. If no step is given, the form_prefix will determine the current step automatically. """

        if step is None:
            step = self.steps.current
        return str(step)