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: nested_delete_inside_update.rs
    path of file: ./repos/prisma-engines/query-engine/connector-test-kit-rs/query-engine-tests/tests/writes/nested_mutations/already_converted
    
    the code of the file until where you have to start completion: use query_engine_tests::*;

#[test_suite]
mod delete_inside_update {
    use query_engine_tests::{assert_error, run_query, run_query_json, DatamodelWithParams};
    use query_test_macros::relation_link_test;

    // ----------------------------------
    // ------------ P1 to C1 ------------
    // ----------------------------------

    // "a P1 to C1  relation "should "work through a nested mutation by id"
    #[relation_link_test(on_parent = "ToOneOpt", on_child = "ToOneOpt")]
    async fn p1_c1_mut_by_id(runner: &Runner, t: &DatamodelWithParams) -> TestResult<()> {
        let parent = t.parent().parse(
            run_query_json!(
                runner,
                format!(
                    r#"mutation {{
                      createOneParent(data: {{
                        p: "existingParent", p_1: "p", p_2: "1",
                        childOpt: {{
                          create: {{c: "existingChild", c_1: "c", c_2: "1"}}

    
    async fn pm_c1_req_by_id_should_work(runner: &Runner, t: &DatamodelWithParams) -> TestResult<()> {
        let parent = t.parent().parse(
            run_query_json!(
                runner,
                format!(
                    r#"mutation {{
                      createOneParent(data: {{
                        p: "p1", p_1: "p", p_2: "1",
                        childrenOpt: {{
                          create: [{{c: "c1", c_1: "c", c_2: "1" }},{{c: "c2", c_1: "c", c_2: "2" }}]
                        }}
                      }}){{
                        {parent_selection}
                        childrenOpt {{
                          {child_selection}
                        }}
                      }}
                    }}"#,
                    parent_selection = t.parent().selection(),
                    child_selection = t.child().selection()
                )
            ),
            &["data", "createOneParent"],
        )?;
        let child = t.child().parse(
            run_query_json!(
                runner,
                format!(
                    r#"query {{
                      findUniqueChild(where: {{c: "c1"}}){{
                        {selection}
                      }}
                    }}"#,
                    selection = t.child().selection()
                )
            ),
            &["data", "findUniqueChild"],
        )?;

        insta::assert_snapshot!(
          run_query!(runner, format!(r#"mutation {{
            updateOneParent(
              where: {parent}
              data:{{
                childrenOpt: {{delete: {child}}}
              }}
            ){{
              childrenOpt {{
                c
              }}
            }}
          }}"#)),
          @r###"{"data":{"updateOneParent":{"childrenOpt":[{"c":"c2"}]}}}"###
        );

        Ok(())
    }