public final MethodWriter visitMethod(
            int access,
            String name,
            String descriptor,
            int codeInitCapacity
    ) {
        MethodWriter methodWriter =
                new MethodWriter(symbolTable, access, name, descriptor, codeInitCapacity);
        if (firstMethod == null) {
            firstMethod = methodWriter;
        } else {
            lastMethod.mv = methodWriter;
        }
        return lastMethod = methodWriter;
    }
The fields of this class, stored in a linked list of {@link FieldWriter} linked via their
{@link FieldWriter#fv} field. This field stores the last element of this list.
core/src/main/java/com/alibaba/fastjson2/internal/asm/ClassWriter.java