public void iconst_n(int n) {
        switch (n) {
            case 0:
                iconst_0();
                break;
            case 1:
                iconst_1();
                break;
            case 2:
                iconst_2();
                break;
            case 3:
                iconst_3();
                break;
            case 4:
                iconst_4();
                break;
            case 5:
                iconst_5();
                break;
            case -1:
                iconst_m1();
                break;
            default:
                if (n >= -128 && n < 127) {
                    bipush(n);
                } else if (n >= -32768 && n < 32767) {
                    sipush(n);
                } else {
                    visitLdcInsn(n);
                }
                break;
        }
    }
Constructs a new {@link MethodWriter}.

@param symbolTable where the constants used in this AnnotationWriter must be stored.
@param access      the method's access flags (see {@link Opcodes}).
@param name        the method's name.
@param descriptor  the method's descriptor (see {@link Type}).
core/src/main/java/com/alibaba/fastjson2/internal/asm/MethodWriter.java