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: _active_trusted_key_groups.rs
    path of file: ./repos/aws-sdk-rust/sdk/cloudfront/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 list of key groups, and the public keys in each key group, that CloudFront can use to verify the signatures of signed URLs and signed cookies.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct Ac
    
    pub fn build(self) -> ::std::result::Result<crate::types::ActiveTrustedKeyGroups, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::ActiveTrustedKeyGroups {
            enabled: self.enabled.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "enabled",
                    "enabled was not specified but it is required when building ActiveTrustedKeyGroups",
                )
            })?,
            quantity: self.quantity.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "quantity",
                    "quantity was not specified but it is required when building ActiveTrustedKeyGroups",
                )
            })?,
            items: self.items,
        })
    }