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: _association_status.rs
    path of file: ./repos/aws-sdk-rust/sdk/ssm/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>Describes an association status.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct AssociationStatus {
    /// <p>The date when the status changed.</p>
    pub date: ::aws_smithy_types::DateTime,
    /// <p>The status.</p>
    pub name: crate::types::AssociationStatusName,
    /// <p>The reason for the status.</p>
    pub message: ::std::string::String,
    /// <p>A user-defined string.</p>
    pub additional_info: ::std::option::Option<::std::string::String>,
}
impl AssociationStatus {
    /// <p>The date when the status changed.</p>
    pub fn date(&self) -> &::aws_smithy_types::DateTime {
        &self.date
    }
  
    
    pub fn build(self) -> ::std::result::Result<crate::types::AssociationStatus, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::AssociationStatus {
            date: self.date.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "date",
                    "date was not specified but it is required when building AssociationStatus",
                )
            })?,
            name: self.name.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "name",
                    "name was not specified but it is required when building AssociationStatus",
                )
            })?,
            message: self.message.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "message",
                    "message was not specified but it is required when building AssociationStatus",
                )
            })?,
            additional_info: self.additional_info,
        })
    }