You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/Theseus/kernel/interrupts/src/x86_64
    
    the code of the file until where you have to start completion: pub use pic::IRQ_BASE_OFFSET;

// use rtc;
use apic::{INTERRUPT_CHIP, InterruptChip};
use cpu::CpuId;
use locked_idt::LockedIdt;
use log::{error, warn, info, debug};
use memory::VirtualAddress;
use spin::Once;
use early_printer::println;

pub use x86_64::structures::idt::{InterruptStackFrame, HandlerFunc as InterruptHandler};
pub type Interru
    
pub fn register_msi_interrupt(func: InterruptHandler) -> Result<u8, &'static str> {
    let mut idt = IDT.lock();

    // try to find an unused interrupt number in the IDT
    let interrupt_num = idt.slice(32..=255)
        .iter()
        .rposition(|&entry| entry.handler_addr().as_u64() as usize == unimplemented_interrupt_handler as usize)
        .map(|entry| entry + 32)
        .ok_or("register_msi_interrupt: no available interrupt handlers (BUG: IDT is full?)")?;

    idt[interrupt_num].set_handler_fn(func);
    
    Ok(interrupt_num as u8)
} 