def METHOD_NAME(self):
    class CustomVisitor(self.asdl.VisitorBase):
        def __init__(self):
            super().__init__()
            self.names_with_seq = []
        def visitModule(self, mod):
            for dfn in mod.dfns:
                self.visit(dfn)
        def visitType(self, type):
            self.visit(type.value)
        def visitSum(self, sum):
            for t in sum.types:
                self.visit(t)
        def visitConstructor(self, cons):
            for f in cons.fields:
                if f.seq:
                    self.names_with_seq.append(cons.name)
    v = CustomVisitor()
    v.visit(self.types['mod'])
    self.assertEqual(v.names_with_seq,
                     ['Module', 'Module', 'Interactive', 'FunctionType'])