You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: shape_region.rs
    path of file: ./repos/aws-sdk-rust/sdk/s3control/src/protocol_serde
    
    the code of the file until where you have to start completion: // Code generated by software.amazon.smithy.rust.codegen.smithy-rs. DO NOT EDIT.
pub fn ser_region(
    input: &crate::types::Region,
    writer: ::aws_smithy_xml::encode::ElWriter,
) -> Result<(), ::aws_smithy_types::error::operation::SerializationError> {
    #[allow(unused_mut)]
    let mut scope = writer.finish();
    {
        let mut inner_writer = scope.start_el("Bucket").finish();
        inner_writer.data(input.bucket.as_str());
    }
    if let Some(var_1) = &input.bucket_account_id {
        let mut inner_writer = scope.start_el("BucketAccountId").finish();
        inner_writer.data(var_1.as_str());
    }
    scope.finish();
    Ok(())
}

#[allow(clippy::needless_question_mark)]
pub fn de_region(decoder: &mut ::aws_smithy_xml::decode::ScopedDecoder) -> Result<crate::types::Region, ::aws_smithy_xml::decode::XmlDecodeE
    
pub fn de_region(decoder: &mut ::aws_smithy_xml::decode::ScopedDecoder) -> Result<crate::types::Region, ::aws_smithy_xml::decode::XmlDecodeError> {
    #[allow(unused_mut)]
    let mut builder = crate::types::Region::builder();
    while let Some(mut tag) = decoder.next_tag() {
        match tag.start_el() {
            s if s.matches("Bucket") /* Bucket com.amazonaws.s3control#Region$Bucket */ =>  {
                let var_2 =
                    Some(
                        Result::<::std::string::String, ::aws_smithy_xml::decode::XmlDecodeError>::Ok(
                            ::aws_smithy_xml::decode::try_data(&mut tag)?.as_ref()
                            .into()
                        )
                        ?
                    )
                ;
                builder = builder.set_bucket(var_2);
            }
            ,
            s if s.matches("BucketAccountId") /* BucketAccountId com.amazonaws.s3control#Region$BucketAccountId */ =>  {
                let var_3 =
                    Some(
                        Result::<::std::string::String, ::aws_smithy_xml::decode::XmlDecodeError>::Ok(
                            ::aws_smithy_xml::decode::try_data(&mut tag)?.as_ref()
                            .into()
                        )
                        ?
                    )
                ;
                builder = builder.set_bucket_account_id(var_3);
            }
            ,
            _ => {}
        }
    }
    Ok(crate::serde_util::region_correct_errors(builder)
        .build()
        .map_err(|_| ::aws_smithy_xml::decode::XmlDecodeError::custom("missing field"))?)
}