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: _rds_field_mapping.rs
    path of file: ./repos/aws-sdk-rust/sdk/bedrockagent/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.

/// A mapping of Bedrock Knowledge Base fields to RDS column names
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct RdsFieldMapping {
    /// Name of the column
    pub primary_key_field: ::std::string::String,
    /// Name of the column
    pub vector_field: ::std::string::String,
    /// Name of the column
    pub text_field: ::std::string::String,
    /// Name of the column
    pub metadata_field: ::std::string::String,
}
impl RdsFieldMapping {
    /// Name of the column
    pub fn primary_key_field(&self) -> &str {
        use std::ops::Deref;
        self.primary_key_field.deref()
    }
    /// Name of the column
    pub fn vector_field(&self) -> &str {
        use std::ops::Deref;
        self.vector_field.deref()
    }
    /// Name of the column
    pub fn text_field(&self) -> &str {
        use std::ops::Deref;
        self.text_field.deref()
    }
    /// Name of the column
    pub fn metadata_field(&self) -> &str {
        use std::ops::Deref;
        self.metadata_field.deref()
    }
}
impl RdsFieldMapping {
    /// Creates a new builder-style object to ma
    
    pub fn build(self) -> ::std::result::Result<crate::types::RdsFieldMapping, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::RdsFieldMapping {
            primary_key_field: self.primary_key_field.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "primary_key_field",
                    "primary_key_field was not specified but it is required when building RdsFieldMapping",
                )
            })?,
            vector_field: self.vector_field.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "vector_field",
                    "vector_field was not specified but it is required when building RdsFieldMapping",
                )
            })?,
            text_field: self.text_field.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "text_field",
                    "text_field was not specified but it is required when building RdsFieldMapping",
                )
            })?,
            metadata_field: self.metadata_field.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "metadata_field",
                    "metadata_field was not specified but it is required when building RdsFieldMapping",
                )
            })?,
        })
    }