List comprehensions the way they are done in Python 2 and
        sometimes in Python 3.
        They're more other comprehensions, e.g. set comprehensions
        See if we can combine code.

def listcomprehension_walk2(self, node):
        """List comprehensions the way they are done in Python 2 and
        sometimes in Python 3.
        They're more other comprehensions, e.g. set comprehensions
        See if we can combine code.
        """
        p = self.prec
        self.prec = 27

        code = Code(node[1].attr, self.scanner, self.currentclass)
        ast = self.build_ast(code._tokens, code._customize)
        self.customize(code._customize)

        # skip over: sstmt, stmt, return, ret_expr
        # and other singleton derivations
        while (len(ast) == 1
               or (ast in ('sstmt', 'return')
                   and ast[-1] in ('RETURN_LAST', 'RETURN_VALUE'))):
            self.prec = 100
            ast = ast[0]

        n = ast[1]
        # collection = node[-3]
        collections = [node[-3]]
        list_ifs = []

        if self.version == 3.0 and n != 'list_iter':
            # FIXME 3.0 is a snowflake here. We need
            # special code for this. Not sure if this is totally
            # correct.
            stores = [ast[3]]
            assert ast[4] == 'comp_iter'
            n = ast[4]
            # Find the list comprehension body. It is the inner-most
            # node that is not comp_.. .
            while n == 'comp_iter':
                if n[0] == 'comp_for':
                    n = n[0]
                    stores.append(n[2])
                    n = n[3]
                elif n[0] in ('comp_if', 'comp_if_not'):
                    n = n[0]
                    # FIXME: just a guess
                    if n[0].kind == 'expr':
                        list_ifs.append(n)
                    else:
                        list_ifs.append([1])
                    n = n[2]
                    pass
                else:
                    break
                pass

            # Skip over n[0] which is something like: _[1]
            self.preorder(n[1])

        else:
            assert n == 'list_iter'
            stores = []
            # Find the list comprehension body. It is the inner-most
            # node that is not list_.. .
            while n == 'list_iter':
                n = n[0] # recurse one step
                if n == 'list_for':
                    stores.append(n[2])
                    n = n[3]
                    if self.version >= 3.6 and n[0] == 'list_for':
                        # Dog-paddle down largely singleton reductions
                        # to find the collection (expr)
                        c = n[0][0]
                        if c == 'expr':
                            c = c[0]
                        # FIXME: grammar is wonky here? Is this really an attribute?
                        if c == 'attribute':
                            c = c[0]
                        collections.append(c)
                        pass
                elif n in ('list_if', 'list_if_not'):
                    # FIXME: just a guess
                    if n[0].kind == 'expr':
                        list_ifs.append(n)
                    else:
                        list_ifs.append([1])
                    n = n[2]
                    pass
                pass

            assert n == 'lc_body', ast
            self.preorder(n[0])

        # FIXME: add indentation around "for"'s and "in"'s
        if self.version < 3.6:
            self.write(' for ')
            self.preorder(stores[0])
            self.write(' in ')
            self.preorder(collections[0])
            if list_ifs:
                self.preorder(list_ifs[0])
                pass
        else:
            for i, store in enumerate(stores):
                self.write(' for ')
                self.preorder(store)
                self.write(' in ')
                self.preorder(collections[i])
                if i < len(list_ifs):
                    self.preorder(list_ifs[i])
                    pass
                pass
        self.prec = p