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: _list_links_output.rs
    path of file: ./repos/aws-sdk-rust/sdk/oam/src/operation/list_links
    
    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.
#[allow(missing_docs)] // documentation missing in model
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct ListLinksOutput {
    /// <p>An array of structures that contain the information about the returned links.</p>
    pub items: ::std::vec::Vec<crate::types::ListLinksItem>,
    /// <p>The token to use when requesting the next set of links.</p>
    pub next_token: ::std::option
    
    pub fn build(self) -> ::std::result::Result<crate::operation::list_links::ListLinksOutput, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::operation::list_links::ListLinksOutput {
            items: self.items.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "items",
                    "items was not specified but it is required when building ListLinksOutput",
                )
            })?,
            next_token: self.next_token,
            _request_id: self._request_id,
        })
    }