This method is only available on newer versions.
The first available version (v2_6_3) is shown here.
rewind()
public
Rewinds the enumerator chain by calling the “rewind” method on each enumerable in reverse order.
Each call is
performed only if the enumerable responds to the method.
static VALUE
enum_chain_rewind(VALUE obj)
{
struct enum_chain *objptr = enum_chain_ptr(obj);
VALUE enums = objptr->enums;
long i;
for (i = objptr->pos; 0 <= i && i < RARRAY_LEN(enums); objptr->pos = --i) {
rb_check_funcall(RARRAY_AREF(enums, i), id_rewind, 0, 0);
}
return obj;
}