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: lib.rs
    path of file: ./repos/solana/programs/sbf/rust/big_mod_exp/src
    
    the code of the file until where you have to start completion: //! Big_mod_exp Syscall tests

extern crate solana_program;
use solana_program::{big_mod_exp::big_mod_exp, custom_panic_default, msg};

fn big_mod_exp_test() {
    #[derive(serde::Deserialize)]
    #[serde(rename_all = "PascalCase")]
    struct TestCa
    
fn big_mod_exp_test() {
    #[derive(serde::Deserialize)]
    #[serde(rename_all = "PascalCase")]
    struct TestCase {
        base: String,
        exponent: String,
        modulus: String,
        expected: String,
    }

    let test_data = r#"[
        {
            "Base":     "1111111111111111111111111111111111111111111111111111111111111111",
            "Exponent": "1111111111111111111111111111111111111111111111111111111111111111",
            "Modulus":  "111111111111111111111111111111111111111111111111111111111111110A",
            "Expected": "0A7074864588D6847F33A168209E516F60005A0CEC3F33AAF70E8002FE964BCD"
        },
        {
            "Base":     "2222222222222222222222222222222222222222222222222222222222222222",
            "Exponent": "2222222222222222222222222222222222222222222222222222222222222222",
            "Modulus":  "1111111111111111111111111111111111111111111111111111111111111111",
            "Expected": "0000000000000000000000000000000000000000000000000000000000000000"
        },
        {
            "Base":     "3333333333333333333333333333333333333333333333333333333333333333",
            "Exponent": "3333333333333333333333333333333333333333333333333333333333333333",
            "Modulus":  "2222222222222222222222222222222222222222222222222222222222222222",
            "Expected": "1111111111111111111111111111111111111111111111111111111111111111"
        },
        {
            "Base":     "9874231472317432847923174392874918237439287492374932871937289719",
            "Exponent": "0948403985401232889438579475812347232099080051356165126166266222",
            "Modulus":  "25532321a214321423124212222224222b242222222222222222222222222444",
            "Expected": "220ECE1C42624E98AEE7EB86578B2FE5C4855DFFACCB43CCBB708A3AB37F184D"
        },
        {
            "Base":     "3494396663463663636363662632666565656456646566786786676786768766",
            "Exponent": "2324324333246536456354655645656616169896565698987033121934984955",
            "Modulus":  "0218305479243590485092843590249879879842313131156656565565656566",
            "Expected": "012F2865E8B9E79B645FCE3A9E04156483AE1F9833F6BFCF86FCA38FC2D5BEF0"
        },
        {
            "Base":     "0000000000000000000000000000000000000000000000000000000000000005",
            "Exponent": "0000000000000000000000000000000000000000000000000000000000000002",
            "Modulus":  "0000000000000000000000000000000000000000000000000000000000000007",
            "Expected": "0000000000000000000000000000000000000000000000000000000000000004"
        },
        {
            "Base":     "0000000000000000000000000000000000000000000000000000000000000019",
            "Exponent": "0000000000000000000000000000000000000000000000000000000000000019",
            "Modulus":  "0000000000000000000000000000000000000000000000000000000000000064",
            "Expected": "0000000000000000000000000000000000000000000000000000000000000019"
        },
        {
            "Base":     "0000000000000000000000000000000000000000000000000000000000000019",
            "Exponent": "0000000000000000000000000000000000000000000000000000000000000019",
            "Modulus":  "0000000000000000000000000000000000000000000000000000000000000000",
            "Expected": "0000000000000000000000000000000000000000000000000000000000000000"
        },
        {
            "Base":     "0000000000000000000000000000000000000000000000000000000000000019",
            "Exponent": "0000000000000000000000000000000000000000000000000000000000000019",
            "Modulus":  "0000000000000000000000000000000000000000000000000000000000000001",
            "Expected": "0000000000000000000000000000000000000000000000000000000000000000"
        }
    ]"#;

    let test_cases: Vec<TestCase> = serde_json::from_str(test_data).unwrap();
    test_cases.iter().for_each(|test| {
        let base = array_bytes::hex2bytes_unchecked(&test.base);
        let exponent = array_bytes::hex2bytes_unchecked(&test.exponent);
        let modulus = array_bytes::hex2bytes_unchecked(&test.modulus);
        let expected = array_bytes::hex2bytes_unchecked(&test.expected);
        let result = big_mod_exp(base.as_slice(), exponent.as_slice(), modulus.as_slice());
        assert_eq!(result, expected);
    });
}