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: lib.rs
    path of file: ./repos/influxdb/iox_query_influxql_rewrite/src
    
    the code of the file until where you have to start completion: use std::collections::HashSet;

use influxdb_influxql_parser::{
    common::ParseError,
    explain::ExplainStatement,
    identifier::Identifier,
    parse_statements as parse_internal,
    select::{MeasurementSelection, SelectStatement},
    show_
    
    fn show_tag_values() {
        TestCase {
            input: "SHOW TAG VALUES WITH KEY = host",
            expected: "SHOW TAG VALUES WITH KEY = host",
            db: None,
            rp: None,
        }
        .assert();
        TestCase {
            input: "SHOW TAG VALUES FROM cpu WITH KEY = host",
            expected: "SHOW TAG VALUES FROM cpu WITH KEY = host",
            db: None,
            rp: None,
        }
        .assert();
        TestCase {
            input: "SHOW TAG VALUES ON foo WITH KEY = host",
            expected: "SHOW TAG VALUES WITH KEY = host",
            db: Some("foo"),
            rp: None,
        }
        .assert();
        TestCase {
            input: "SHOW TAG VALUES ON foo FROM cpu WITH KEY = host",
            expected: "SHOW TAG VALUES FROM cpu WITH KEY = host",
            db: Some("foo"),
            rp: None,
        }
        .assert();
    }