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: _lambda_action.rs
    path of file: ./repos/aws-sdk-rust/sdk/ses/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>When included in a receipt rule, this action calls an Amazon Web Services Lambda function and, optionally, publishes a notification to Amazon Simple Notification Service (Amazon SNS).</p>
/// <p>To enable Amazon SES to call your Amazon Web Services Lambda function or to publish to an Amazon SNS topic of another accou
    
    pub fn build(self) -> ::std::result::Result<crate::types::LambdaAction, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::LambdaAction {
            topic_arn: self.topic_arn,
            function_arn: self.function_arn.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "function_arn",
                    "function_arn was not specified but it is required when building LambdaAction",
                )
            })?,
            invocation_type: self.invocation_type,
        })
    }