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: _page_classification.rs
    path of file: ./repos/aws-sdk-rust/sdk/textract/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 class assigned to a Page object detected in an input document. Contains information regarding the predicted type/class of a document's page and the page number that the Page object was detected on.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct PageClassification {
    /// <p>The class, or document type, assigned to a de
    
    pub fn build(self) -> ::std::result::Result<crate::types::PageClassification, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::PageClassification {
            page_type: self.page_type.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "page_type",
                    "page_type was not specified but it is required when building PageClassification",
                )
            })?,
            page_number: self.page_number.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "page_number",
                    "page_number was not specified but it is required when building PageClassification",
                )
            })?,
        })
    }