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: _thing_group_indexing_configuration.rs
    path of file: ./repos/aws-sdk-rust/sdk/iot/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>Thing group indexing configuration.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct ThingGroupIndexingConfiguration {
    /// <p>Thing group indexing mode.</p>
    pub thing_group_indexing_mode: crate::types::ThingGroupIndexingMode,
    /// <p>Conta
    
    pub fn build(self) -> ::std::result::Result<crate::types::ThingGroupIndexingConfiguration, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::ThingGroupIndexingConfiguration {
            thing_group_indexing_mode: self.thing_group_indexing_mode.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "thing_group_indexing_mode",
                    "thing_group_indexing_mode was not specified but it is required when building ThingGroupIndexingConfiguration",
                )
            })?,
            managed_fields: self.managed_fields,
            custom_fields: self.custom_fields,
        })
    }