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: func_refs.rs
    path of file: ./repos/wasmtime/crates/wasmtime/src/runtime/store
    
    the code of the file until where you have to start completion: use crate::module::ModuleRegistry;
use std::{ptr::NonNull, sync::Arc};
use wasmtime_runtime::{SendSyncPtr, VMFuncRef, VMNativeCallHostFuncContext};

/// An arena of `VMFuncRef`s.
///
/// Allows a store to pin 
    
    pub unsafe fn push(&mut self, func_ref: VMFuncRef) -> NonNull<VMFuncRef> {
        debug_assert!(func_ref.wasm_call.is_none());
        // Debug assert that the vmctx is a `VMNativeCallHostFuncContext` as
        // that is the only kind that can have holes.
        let _ = unsafe { VMNativeCallHostFuncContext::from_opaque(func_ref.vmctx) };

        let func_ref = self.bump.alloc(func_ref);
        let unpatched = SendSyncPtr::from(func_ref);
        let ret = unpatched.as_non_null();
        self.with_holes.push(unpatched);
        ret
    }