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: _asset_entry.rs
    path of file: ./repos/aws-sdk-rust/sdk/dataexchange/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>An asset in AWS Data Exchange is a piece of data (Amazon S3 object) or a means of fulfilling data (Amazon Redshift datashare or Amazon API Gateway API, AWS Lake Formation data permission, or Amazon S3 data access). The asset can be a structured data file, an image file, or some other data file that can be stored as an Amazon S3 object,
    
    pub fn build(self) -> ::std::result::Result<crate::types::AssetEntry, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::AssetEntry {
            arn: self.arn.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "arn",
                    "arn was not specified but it is required when building AssetEntry",
                )
            })?,
            asset_details: self.asset_details,
            asset_type: self.asset_type.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "asset_type",
                    "asset_type was not specified but it is required when building AssetEntry",
                )
            })?,
            created_at: self.created_at.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "created_at",
                    "created_at was not specified but it is required when building AssetEntry",
                )
            })?,
            data_set_id: self.data_set_id.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "data_set_id",
                    "data_set_id was not specified but it is required when building AssetEntry",
                )
            })?,
            id: self.id.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "id",
                    "id was not specified but it is required when building AssetEntry",
                )
            })?,
            name: self.name.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "name",
                    "name was not specified but it is required when building AssetEntry",
                )
            })?,
            revision_id: self.revision_id.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "revision_id",
                    "revision_id was not specified but it is required when building AssetEntry",
                )
            })?,
            source_id: self.source_id,
            updated_at: self.updated_at.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "updated_at",
                    "updated_at was not specified but it is required when building AssetEntry",
                )
            })?,
        })
    }