Function assoc_set 

pub fn assoc_set<T0, T1>(
    name: &str,
    key: T0,
    value: T1,
) -> Result<(), VariableError>
where
    T0: AsRef<[u8]>,
    T1: AsRef<[u8]>,

Change an element of the associative array contained in the shell variable referenced by name.

value is not required to be valid UTF-8, but it can’t contain any nul byte.