Function handle_section 

fn handle_section<'wasm, T, F>(
    wasm: &mut WasmReader<'wasm>,
    header: &mut Option<SectionHeader>,
    section_ty: SectionTy,
    handler: F,
) -> Result<Option<T>, ValidationError>
where
    T: 'wasm,
    F: FnOnce(&mut WasmReader<'wasm>, SectionHeader) -> Result<T, ValidationError>,