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: _comment.rs
    path of file: ./repos/aws-sdk-rust/sdk/workdocs/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 a comment.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq)]
pub struct Comment {
    /// <p>The ID of the comment.</p>
    pub comment_id: ::std::string::String,
    /// <p>The ID of the parent comment.</p>
    pub parent_id: ::std::option::Option<::std::string::String>,
    /// <p>The ID of the root comment in the thread.</p>
    pub thread_id: ::std::option::Option<::std::string::String>,
    
    pub fn build(self) -> ::std::result::Result<crate::types::Comment, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::Comment {
            comment_id: self.comment_id.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "comment_id",
                    "comment_id was not specified but it is required when building Comment",
                )
            })?,
            parent_id: self.parent_id,
            thread_id: self.thread_id,
            text: self.text,
            contributor: self.contributor,
            created_timestamp: self.created_timestamp,
            status: self.status,
            visibility: self.visibility,
            recipient_id: self.recipient_id,
        })
    }