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: _update_routing_control_state_entry.rs
    path of file: ./repos/aws-sdk-rust/sdk/route53recoverycluster/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>A routing control state entry.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct UpdateRoutingControlStateEntry {
    /// <p>The Amazon Resource Name (ARN) for a routing control state entry.</p>
    pub routing_control_arn: ::std::string::String,
    /// <p>The routing control st
    
    pub fn build(self) -> ::std::result::Result<crate::types::UpdateRoutingControlStateEntry, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::UpdateRoutingControlStateEntry {
            routing_control_arn: self.routing_control_arn.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "routing_control_arn",
                    "routing_control_arn was not specified but it is required when building UpdateRoutingControlStateEntry",
                )
            })?,
            routing_control_state: self.routing_control_state.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "routing_control_state",
                    "routing_control_state was not specified but it is required when building UpdateRoutingControlStateEntry",
                )
            })?,
        })
    }