def bind(self, typevar, its_type):
assert type(typevar) == tg.TypeVar<EOL>if self.is_generic_in(typevar):<EOL><INDENT>self.bind_to_instance(typevar, its_type)<EOL><DEDENT>else:<EOL><INDENT>self._ns[typevar] = its_type<EOL><DEDENT>
Binds typevar to the type its_type.
Binding occurs on the instance if the typevar is a TypeVar of the
generic type of the instance, on call level otherwise.