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: _backup_plan_input.rs
    path of file: ./repos/aws-sdk-rust/sdk/backup/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>Contains an optional backup plan display name and an array of <code>BackupRule</code> objects, each of which specifies a backup rule. Each rule in a backup plan is a separate scheduled task.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct BackupPlanInput {
    /// <p>The display name of a backup plan. Must contain 1 to 50 alphanumeric or '-_.' characters.</p>
    pub backup_plan_name: ::std::string::String,
    /// <p>An array of <code>BackupRule</code> objects, each of which specifies a scheduled task that is used to back up a selection of resources.</p>
    pub rules: ::std::vec::Vec<crate::types::BackupRuleInput>,
    /// <p>Specifies a lis
    
    pub fn build(self) -> ::std::result::Result<crate::types::BackupPlanInput, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::BackupPlanInput {
            backup_plan_name: self.backup_plan_name.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "backup_plan_name",
                    "backup_plan_name was not specified but it is required when building BackupPlanInput",
                )
            })?,
            rules: self.rules.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "rules",
                    "rules was not specified but it is required when building BackupPlanInput",
                )
            })?,
            advanced_backup_settings: self.advanced_backup_settings,
        })
    }