def Bulged(strand):
        """
        Return absolute position of bulge in input strand if present. Otherwise, return None.
        """
        flag=False ; bulgepos=None
        for i in range(1,len(strand.bp_data)-1):
                prev_res = strand.bp_data[i-1]
                res = strand.bp_data[i]
                next_res = strand.bp_data[i+1]
                if 'EA' == res[2] and 'EB' == prev_res[2] and 'EB' == next_res[2]:
                    flag=True
                    bulgepos = res[0]
        return bulgepos