How to use the snowballstemmer.english_stemmer.lab0 function in snowballstemmer

def r_prelude(self):
        # (, line 25
        # unset Y_found, line 26
        self.B_Y_found = False
        # do, line 27
        v_1 = self.cursor
        try:
            # (, line 27
            # [, line 27
            self.bra = self.cursor
            # literal, line 27
            if not self.eq_s(1, u"'"):
                raise lab0()
            # ], line 27
            self.ket = self.cursor
            # delete, line 27
            if not self.slice_del():
                return False

        except lab0: pass
        self.cursor = v_1
        # do, line 28
        v_2 = self.cursor
        try:
            # (, line 28
            # [, line 28
            self.bra = self.cursor
            # literal, line 28
            if not self.eq_s(1, u"y"):

if not self.r_R1():
                return False
            # <-, line 77
            if not self.slice_from(u"ee"):
                return False
        elif among_var == 2:
            # (, line 79
            # test, line 80
            v_1 = self.limit - self.cursor
            # gopast, line 80
            try:
                while True:
                    try:
                        if not self.in_grouping_b(EnglishStemmer.g_v, 97, 121):
                            raise lab1()
                        raise lab0()
                    except lab1: pass
                    if self.cursor <= self.limit_backward:
                        return False
                    self.cursor -= 1
            except lab0: pass
            self.cursor = self.limit - v_1
            # delete, line 80
            if not self.slice_del():
                return False

            # test, line 81
            v_3 = self.limit - self.cursor
            # substring, line 81
            among_var = self.find_among_b(EnglishStemmer.a_3, 13)
            if among_var == 0:
                return False

# try, line 59
        v_1 = self.limit - self.cursor
        try:
            # (, line 59
            # [, line 60
            self.ket = self.cursor
            # substring, line 60
            among_var = self.find_among_b(EnglishStemmer.a_1, 3)
            if among_var == 0:
                self.cursor = self.limit - v_1
                raise lab0()
            # ], line 60
            self.bra = self.cursor
            if among_var == 0:
                self.cursor = self.limit - v_1
                raise lab0()
            elif among_var == 1:
                # (, line 62
                # delete, line 62
                if not self.slice_del():
                    return False

        except lab0: pass
        # [, line 65
        self.ket = self.cursor
        # substring, line 65
        among_var = self.find_among_b(EnglishStemmer.a_2, 6)
        if among_var == 0:
            return False
        # ], line 65
        self.bra = self.cursor
        if among_var == 0:

def r_shortv(self):
        # (, line 49
        # or, line 51
        try:
            v_1 = self.limit - self.cursor
            try:
                # (, line 50
                if not self.out_grouping_b(EnglishStemmer.g_v_WXY, 89, 121):
                    raise lab1()
                if not self.in_grouping_b(EnglishStemmer.g_v, 97, 121):
                    raise lab1()
                if not self.out_grouping_b(EnglishStemmer.g_v, 97, 121):
                    raise lab1()
                raise lab0()
            except lab1: pass
            self.cursor = self.limit - v_1
            # (, line 52
            if not self.out_grouping_b(EnglishStemmer.g_v, 97, 121):
                return False
            if not self.in_grouping_b(EnglishStemmer.g_v, 97, 121):
                return False
            # atlimit, line 52
            if self.cursor > self.limit_backward:
                return False
        except lab0: pass
        return True

elif among_var == 1:
            # (, line 144
            # delete, line 144
            if not self.slice_del():
                return False

        elif among_var == 2:
            # (, line 145
            # or, line 145
            try:
                v_1 = self.limit - self.cursor
                try:
                    # literal, line 145
                    if not self.eq_s_b(1, u"s"):
                        raise lab1()
                    raise lab0()
                except lab1: pass
                self.cursor = self.limit - v_1
                # literal, line 145
                if not self.eq_s_b(1, u"t"):
                    return False
            except lab0: pass
            # delete, line 145
            if not self.slice_del():
                return False

        return True

def r_Step_1c(self):
        # (, line 93
        # [, line 94
        self.ket = self.cursor
        # or, line 94
        try:
            v_1 = self.limit - self.cursor
            try:
                # literal, line 94
                if not self.eq_s_b(1, u"y"):
                    raise lab1()
                raise lab0()
            except lab1: pass
            self.cursor = self.limit - v_1
            # literal, line 94
            if not self.eq_s_b(1, u"Y"):
                return False
        except lab0: pass
        # ], line 94
        self.bra = self.cursor
        if not self.out_grouping_b(EnglishStemmer.g_v, 97, 121):
            return False
        # not, line 95
        v_2 = self.limit - self.cursor
        try:
            # atlimit, line 95
            if self.cursor > self.limit_backward:
                raise lab2()

if self.find_among(EnglishStemmer.a_0, 3) == 0:
                        raise lab2()
                    raise lab1()
                except lab2: pass
                self.cursor = v_2
                # (, line 41
                # gopast, line 41
                try:
                    while True:
                        try:
                            if not self.in_grouping(EnglishStemmer.g_v, 97, 121):
                                raise lab4()
                            raise lab3()
                        except lab4: pass
                        if self.cursor >= self.limit:
                            raise lab0()
                        self.cursor += 1
                except lab3: pass
                # gopast, line 41
                try:
                    while True:
                        try:
                            if not self.out_grouping(EnglishStemmer.g_v, 97, 121):
                                raise lab6()
                            raise lab5()
                        except lab6: pass
                        if self.cursor >= self.limit:
                            raise lab0()
                        self.cursor += 1
                except lab5: pass
            except lab1: pass
            # setmark p1, line 42

self.ket = self.cursor
                                    self.cursor = v_2
                                    raise lab3()
                                except lab4: pass
                                self.cursor = v_2
                                if self.cursor >= self.limit:
                                    raise lab2()
                                self.cursor += 1
                        except lab3: pass
                        # <-, line 203
                        if not self.slice_from(u"y"):
                            return False
                        raise lab1()
                    except lab2: pass
                    self.cursor = v_1
                    raise lab0()
                except lab1: pass
        except lab0: pass
        return True

if among_var == 0:
            return False
        # ], line 150
        self.bra = self.cursor
        if among_var == 0:
            return False
        elif among_var == 1:
            # (, line 151
            # or, line 151
            try:
                v_1 = self.limit - self.cursor
                try:
                    # call R2, line 151
                    if not self.r_R2():
                        raise lab1()
                    raise lab0()
                except lab1: pass
                self.cursor = self.limit - v_1
                # (, line 151
                # call R1, line 151
                if not self.r_R1():
                    return False
                # not, line 151
                v_2 = self.limit - self.cursor
                try:
                    # call shortv, line 151
                    if not self.r_shortv():
                        raise lab2()
                    return False
                except lab2: pass
                self.cursor = self.limit - v_2
            except lab0: pass