Macro putStringBuf 

macro_rules! putStringBuf {
    ($val:ident,$key:ident,$typ:ident,$slf:ident.$($x:ident).+,$pad:expr_2021) => { ... };
}

Put a fixed length UTF8 string into the image using the given key path.

putString!(val:&str,key_path:&Vec<String>,image_type:String,self.path.to.buf:[u8],pad:u8)