How does asmjit get code relocation when use AsmParser(&a).parse

I use asmjit in my c++ code and defined a function like below:

    // parse asm_str to byte code, return the length of byte code
    int assemble(bool isx64, unsigned long long addr, const char* asm_str, char buffer[MAX_INSTRUCTION_LENGTH])
    {
        // for test, I modified param's value
        isx64 = true;
        addr = 0x6a9ec0;
        asm_str = "call 0x00007FFF1CF8CEE0";

        auto arch = isx64 ? Arch::kX64 : Arch::kX86;

        // Initialize Environment with the requested architecture.
        Environment environment;
        environment.setArch(arch);

        // Initialize CodeHolder.
        CodeHolder code;
        Error err = code.init(environment, addr);

        if (err) {
            dbg_print_err("code.init failed, reason:%s", DebugUtils::errorAsString(err));
            return 0;
        }
        x86::Assembler a(&code);
        err = AsmParser(&a).parse(asm_str, strlen(asm_str));

        if (err) {
            dbg_print_err("AsmParser(&a).parse failed, asm_str=\"%s\" addr=0x%llx reason:%s", asm_str, addr, DebugUtils::errorAsString(err));
            return 0;
        }
        else {
            CodeBuffer& buf = code.sectionById(0)->buffer();
            memcpy(buffer, buf.data(), buf.size());
            print_byte_hex(buffer, buf.size());
            return (int)buf.size();
        }
    }

When I run this funciton and got the result of buffer is 40 E8 00 00 00 00 and not find any error. Actually, I known about that this instruction could not compile to byte code in addr(0x6a9ec0). So, I want to know how to determine if such instructions are compiled successfully in the code.

How to determine if such instructions are compiled with errors in the byte code.