Unable to conversion in Expected<unique_ptr<Module>> to Module - c++

Question

I am new to llvm , writing the program "main.cpp" of https://github.com/davidar/lljvm/blob/master/backend/main.cpp.
I stuck at the error while executing the command : "pm.run(m)"
error: no matching function for call to ‘llvm::legacy::PassManager::run(llvm::Expected<std::unique_ptr<llvm::Module> >&)
Here is my source code:
#include "backened.h"
#include <iostream>
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/IR/PassManager.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/DataLayout.h"
#include <llvm/Transforms/Scalar.h>
#include "llvm/IR/LegacyPassManager.h"
using namespace llvm;
using namespace std;
static cl::opt<string> input(cl::Positional, cl::desc("Bitcode File.."),cl::Required);
static cl::opt<string> classname("classname",cl::desc("Binary name of the generated class..."));
int main(int argc, char** argv)
{
cl::ParseCommandLineOptions(argc, argv, "Hi..");
LLVMContext context;
ErrorOr<unique_ptr<MemoryBuffer>> mb = MemoryBuffer::getFile(input);
if(error_code ec = mb.getError()) {
errs() << ec.message();
return 1;
}
Expected<unique_ptr<Module>> m = parseBitcodeFile(mb->get()->getMemBufferRef(),context);
if(error_code ec= errorToErrorCode(m.takeError()) )
{
errs() <<"Unable to read bitcode file.." <<ec.message() ;
}
PassManager<Module> pm;
pm.add(createVerifierPass());
pm.add(createGCLoweringPass());
pm.add(createLowerSwitchPass());
pm.add(createCFGSimplificationPass());
pm.add(new JVMWriter(fouts(), classname, debugLevel));
pm.add(createGCInfoDeleter());
pm.run(*m);
return 0;
}
Please help me.