src/org/nutz/repo/org/objectweb/asm/MethodVisitor.java
public void visitFieldInsn(int opcode, String owner, String name,
            String desc) {
        if (mv != null) {
            mv.visitFieldInsn(opcode, owner, name, desc);
        }
    }
public void visitFieldInsn(int opcode, String owner, String name,
            String desc) {
        if (mv != null) {
            mv.visitFieldInsn(opcode, owner, name, desc);
        }
    }
Visits a field instruction. A field instruction is an instruction that
loads or stores the value of a field of an object.

@param opcode
the opcode of the type instruction to be visited. This opcode
is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
@param owner
the internal name of the field's owner class (see
{@link Type#getInternalName() getInternalName}).
@param name
the field's name.
@param desc
the field's descriptor (see {@link Type Type}).