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: _button.rs
    path of file: ./repos/aws-sdk-rust/sdk/lexruntime/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>Represents an option to be shown on the client platform (Facebook, Slack, etc.)</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct Button {
    /// <p>Text that is visible to the user on t
    
    pub fn build(self) -> ::std::result::Result<crate::types::Button, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::Button {
            text: self.text.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "text",
                    "text was not specified but it is required when building Button",
                )
            })?,
            value: self.value.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "value",
                    "value was not specified but it is required when building Button",
                )
            })?,
        })
    }