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: _metric_query.rs
    path of file: ./repos/aws-sdk-rust/sdk/pi/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 single query to be processed. You must provide the metric to query. If no other parameters are specified, Performance Insights returns all data points for the specified metric. Optionally, you can request that the data points b
    
    pub fn build(self) -> ::std::result::Result<crate::types::MetricQuery, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::types::MetricQuery {
            metric: self.metric.ok_or_else(|| {
                ::aws_smithy_types::error::operation::BuildError::missing_field(
                    "metric",
                    "metric was not specified but it is required when building MetricQuery",
                )
            })?,
            group_by: self.group_by,
            filter: self.filter,
        })
    }