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: get.rs
    path of file: ./repos/polars/crates/polars-ops/src/chunked_array/array
    
    the code of the file until where you have to start completion: use arrow::legacy::kernels::fixed_size_list::{
    sub_fixed_size_list_get, sub_fixed_size_list_get_literal,
};
use polars_core::prelude::arity::binary_to_series;

use super::*;

fn array_get_literal(ca: &ArrayChunked, idx: i64) -> PolarsResult<Series> {
    let chunks = ca
        .downcast_iter()
        .map(|arr| sub_fixed_size_list_get_literal(arr, idx))
        .collect::<Vec<_>>();
    Series::try_from((ca.name(), chunks))
        .unwrap()
        .cast(&ca.inner_dtype())
}

/// Get the value by literal index in the array.
/// So index `0` would return t
    
pub fn array_get(ca: &ArrayChunked, index: &Int64Chunked) -> PolarsResult<Series> {
    match index.len() {
        1 => {
            let index = index.get(0);
            if let Some(index) = index {
                array_get_literal(ca, index)
            } else {
                polars_bail!(ComputeError: "unexpected null index received in `arr.get`")
            }
        },
        len if len == ca.len() => {
            let out = binary_to_series(ca, index, |arr, idx| sub_fixed_size_list_get(arr, idx));
            out?.cast(&ca.inner_dtype())
        },
        len => polars_bail!(
            ComputeError:
            "`arr.get` expression got an index array of length {} while the array has {} elements",
            len, ca.len()
        ),
    }
}