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: _s3_destination.rs
    path of file: ./repos/aws-sdk-rust/sdk/bcmdataexports/src/types
    
    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.

/// <p>Describes the destination Amazon Simple Storage Service (Amazon S3) bucket name and object keys of a data exports file.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct S3Destination {
    /// <p>The name of the Amazon S3 bucket used as the destination of a data export file.</p>
    pub s3_bucket: ::std::string::String,
    /// <p>The S3 path prefix you want prepended to the name of your data export.</p>
    pub s3_prefix: ::std::string::String,
    /// <p>The S3 bucket Region.<
    
    pub fn build(self) -> ::std::result::Result<crate::types::S3Destination, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::S3Destination {
            s3_bucket: self.s3_bucket.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "s3_bucket",
                    "s3_bucket was not specified but it is required when building S3Destination",
                )
            })?,
            s3_prefix: self.s3_prefix.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "s3_prefix",
                    "s3_prefix was not specified but it is required when building S3Destination",
                )
            })?,
            s3_region: self.s3_region.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "s3_region",
                    "s3_region was not specified but it is required when building S3Destination",
                )
            })?,
            s3_output_configurations: self.s3_output_configurations,
        })
    }