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: matano_alerts.rs
    path of file: ./repos/matano/lib/rust/lake_writer/src
    
    the code of the file until where you have to start completion: use crate::{
    common::{load_table_arrow_schema, struct_wrap_arrow2_for_ffi, write_arrow_to_s3_parquet},
    ALERTS_TABLE_NAME, AWS_CONFIG,
};
use anyhow::{anyhow, Context, Result};
use arrow2::chunk::Chunk;
use arrow2::datatypes::*;
use arrow2::io::avro::avro_schema;
use arrow2::io::avro::avro_schema::file::{Block, CompressedBlock, Compression};
use arrow2::io::avro::avro_schema::schema::Record;
use arrow2::io::avro::avro_schema::writ
    
async fn call_helper_lambda(payload: String) -> Result<Option<Vec<u8>>> {
    let lambda = LAMBDA_CLIENT.get().await;
    let helper_function_name = std::env::var("ALERT_HELPER_FUNCTION_NAME")?;

    let func_res = lambda
        .invoke()
        .function_name(&helper_function_name)
        .payload(Blob::new(payload))
        .send()
        .await?;

    let resp_payload = func_res.payload().map(|blob| blob.to_owned().into_inner());
    if func_res.function_error().is_some() {
        let err_obj_bytes = resp_payload.unwrap_or_default();
        let err_obj = String::from_utf8_lossy(&err_obj_bytes);
        Err(anyhow!(
            "{} Lambda failed: {}",
            &helper_function_name,
            err_obj
        ))
    } else {
        Ok(resp_payload)
    }
}