if (methodGen == null) return;
	private void scanMethod(Method method, Set<XField> assignableFieldSet) throws ClassNotFoundException {		MethodGen methodGen = classContext.getMethodGen(method);		InstructionList il = methodGen.getInstructionList();		InstructionHandle handle = il.getStart();		ConstantPoolGen cpg = methodGen.getConstantPool();		while (handle != null) {			Instruction ins = handle.getInstruction();			short opcode = ins.getOpcode();			if (opcode == Constants.PUTFIELD) {				PUTFIELD putfield = (PUTFIELD) ins;				XField instanceField = Hierarchy.findXField(putfield, cpg);				if (instanceField != null && assignableFieldSet.contains(instanceField)) {					Set<XField> assignedFieldSetForMethod = getAssignedFieldSetForMethod(method);					assignedFieldSetForMethod.add(instanceField);				}			}			handle = handle.getNext();		}	}