Macro dimension 

macro_rules! dimension {
    ($name:ident $($doc:literal)?) => { ... };
    (
        $( ,$divisor:expr, )?
        $name:ident =
        $( ;$scaling_factor:expr; )?
        $( $( ,$prefix:ident )? $rest:ident $( ^$rest_exp:literal )? )*
        $($doc:literal)?
    ) => { ... };
    ($name:ident = $unit:expr $(=> $doc:literal)?) => { ... };
}

Creates a static LazyLock