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: _registration_association_metadata.rs
    path of file: ./repos/aws-sdk-rust/sdk/pinpointsmsvoicev2/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>Metadata for the origination identity that is associated with the registration.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct RegistrationAssociationMetadata {
    /// <p>The Amazon Resource Name (ARN) of the origination 
    
    pub fn build(self) -> ::std::result::Result<crate::types::RegistrationAssociationMetadata, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::RegistrationAssociationMetadata {
            resource_arn: self.resource_arn.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "resource_arn",
                    "resource_arn was not specified but it is required when building RegistrationAssociationMetadata",
                )
            })?,
            resource_id: self.resource_id.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "resource_id",
                    "resource_id was not specified but it is required when building RegistrationAssociationMetadata",
                )
            })?,
            resource_type: self.resource_type.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "resource_type",
                    "resource_type was not specified but it is required when building RegistrationAssociationMetadata",
                )
            })?,
            iso_country_code: self.iso_country_code,
            phone_number: self.phone_number,
        })
    }