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: _document_classifier_documents.rs
    path of file: ./repos/aws-sdk-rust/sdk/comprehend/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>The location of the training documents. This parameter is required in a request to create a semi-structured document classification model.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct DocumentClassifierDocuments {
    /// <p>The S
    
    pub fn build(self) -> ::std::result::Result<crate::types::DocumentClassifierDocuments, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::DocumentClassifierDocuments {
            s3_uri: self.s3_uri.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "s3_uri",
                    "s3_uri was not specified but it is required when building DocumentClassifierDocuments",
                )
            })?,
            test_s3_uri: self.test_s3_uri,
        })
    }