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_hapgs_output.rs
    path of file: ./repos/aws-sdk-rust/sdk/cloudhsm/src/operation/list_hapgs
    
    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 ListHapgsOutput {
    /// <p>The list of high-availability partition groups.</p>
    pub hapg_list: ::std::vec::Vec<::std::string::String>,
    /// <p>If not null, more results are available. Pass this value to <code>ListHapgs</code> to retrieve the next se
    
    pub fn build(self) -> ::std::result::Result<crate::operation::list_hapgs::ListHapgsOutput, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::operation::list_hapgs::ListHapgsOutput {
            hapg_list: self.hapg_list.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "hapg_list",
                    "hapg_list was not specified but it is required when building ListHapgsOutput",
                )
            })?,
            next_token: self.next_token,
            _request_id: self._request_id,
        })
    }