pub fn math_rand_alpha(n: usize) -> String {
    let mut rng = thread_rng();

    let rand_string: String = (0..n)
        .map(|_| {
            let idx = rng.gen_range(0..RUNES_ALPHA.len());
            RUNES_ALPHA[idx] as char
        })
        .collect();

    rand_string
}
/// math_rand_alpha generates a mathmatical random alphabet sequence of the requested length.
math_rand_alpha generates a mathmatical random alphabet sequence of the requested length.
math_rand_alpha generates a mathmatical random alphabet sequence of the requested length .
pub fn math_rand_alpha(n: usize) -> String {
    let mut rng = thread_rng();
    let rand_string: String = (0..n)
        .map(|_| {
            let idx = rng.gen_range(0..RUNES_ALPHA.len());
            RUNES_ALPHA[idx] as char
        })
        .collect();
    rand_string
}
pub fn math_rand_alpha ( n : usize ) -> String { let mut rng = thread_rng ( ) ; let rand_string : String = ( 0 .. n ) . map ( | _ | { let idx = rng . gen_range ( 0 .. RUNES_ALPHA . len ( ) ) ; RUNES_ALPHA [ idx ] as char } ) . collect ( ) ; rand_string }
math_rand_alpha generates a mathmatical random alphabet sequence of the requested length.
math_rand_alpha generates a mathmatical random alphabet sequence of the requested length .
n
usize