public void insertPushNull(int opcode,JumpInsnNode position,InsnList list){
  int branchId=getBranchID(currentMethodNode,position);
  logger.info("Inserting instrumentation for NULL check at branch " + branchId + " in method "+ currentMethodNode.name);
  MethodInsnNode nullCheck=new MethodInsnNode(Opcodes.INVOKESTATIC,Type.getInternalName(BooleanHelper.class),"isNull",Type.getMethodDescriptor(Type.INT_TYPE,new Type[]{Type.getType(Object.class),Type.INT_TYPE}),false);
  list.insertBefore(position,new InsnNode(Opcodes.DUP));
  list.insertBefore(position,new LdcInsnNode(opcode));
  list.insertBefore(position,nullCheck);
  insertBranchIdPlaceholder(currentMethodNode,position,branchId);
  MethodInsnNode push=new MethodInsnNode(Opcodes.INVOKESTATIC,Type.getInternalName(BooleanHelper.class),"pushPredicate",Type.getMethodDescriptor(Type.VOID_TYPE,new Type[]{Type.INT_TYPE,Type.INT_TYPE}),false);
  list.insertBefore(position,push);
}

public void insertPushNull ( int opcode , JumpInsnNode position , InsnList list ) { int branchId = getBranchID ( currentMethodNode , position ) ; logger . info ( "Inserting instrumentation for NULL check at branch " + branchId + " in method " + currentMethodNode . name ) ; MethodInsnNode nullCheck = new MethodInsnNode ( Opcodes . INVOKESTATIC , Type . getInternalName ( BooleanHelper . class ) , "isNull" , Type . getMethodDescriptor ( Type . INT_TYPE , new Type [ ] { Type . getType ( Object . class ) , Type . INT_TYPE } ) , false ) ; list . insertBefore ( position , new InsnNode ( Opcodes . DUP ) ) ; list . insertBefore ( position , new LdcInsnNode ( opcode ) ) ; list . insertBefore ( position , nullCheck ) ; insertBranchIdPlaceholder ( currentMethodNode , position , branchId ) ; MethodInsnNode push = new MethodInsnNode ( Opcodes . INVOKESTATIC , Type . getInternalName ( BooleanHelper . class ) , "pushPredicate" , Type . getMethodDescriptor ( Type . VOID_TYPE , new Type [ ] { Type . INT_TYPE , Type . INT_TYPE } ) , false ) ; list . insertBefore ( position , push ) ; }
insert a call to the isnull helper function
