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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 _make_valid_state_name(self, state_name):
 """Transform the input state_name into a valid state in XMLBIF. XMLBIF states must start with a letter an only contain letters, numbers and underscores. """

        s = str(state_name)
        s_fixed = pp.CharsNotIn(pp.alphanums + "_").setParseAction(pp.replaceWith("_")).transformString(s)
        if not s_fixed[0].isalpha():
            s_fixed = "state" + s_fixed
        return s_fixed