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: main.rs
    path of file: ./repos/risc0/examples/wasm/src
    
    the code of the file until where you have to start completion: // Copyright 2024 RISC Zero, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use risc0_zkvm::{default_prover, ExecutorEnv};
use wasm_methods::{WASM_INTERP_ELF, WASM_INTERP_ID};

fn wat2wasm(wat: 
    
fn run_guest(iters: i32) -> i32 {
    let wat = r#"
    (module
        (export "fib" (func $fib))
        (func $fib (; 0 ;) (param $0 i32) (result i32)
        (local $1 i32)
        (local $2 i32)
        (local $3 i32)
        (local $4 i32)
        (set_local $4
         (i32.const 1)
        )
        (block $label$0
         (br_if $label$0
          (i32.lt_s
           (get_local $0)
           (i32.const 1)
          )
         )
         (set_local $3
          (i32.const 0)
         )
         (loop $label$1
          (set_local $1
           (i32.add
            (get_local $3)
            (get_local $4)
           )
          )
          (set_local $2
           (get_local $4)
          )
          (set_local $3
           (get_local $4)
          )
          (set_local $4
           (get_local $1)
          )
          (br_if $label$1
           (tee_local $0
            (i32.add
             (get_local $0)
             (i32.const -1)
            )
           )
          )
         )
         (return
          (get_local $2)
         )
        )
        (i32.const 0)
       )
    )
    "#;

    let wasm = wat2wasm(&wat).expect("Failed to parse_str");

    let env = ExecutorEnv::builder()
        .write(&wasm)
        .unwrap()
        .write(&iters)
        .unwrap()
        .build()
        .unwrap();

    // Obtain the default prover.
    let prover = default_prover();

    // Produce a receipt by proving the specified ELF binary.
    let receipt = prover.prove(env, WASM_INTERP_ELF).unwrap();

    receipt.verify(WASM_INTERP_ID).expect(
        "Code you have proven should successfully verify; did you specify the correct image ID?",
    );
    let result: i32 = receipt.journal.decode().unwrap();

    result
}