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: multi_valued_index_test.go
    path of file: ./repos/tidb/pkg/ddl/tests/multivaluedindex
    
    the code of the file until where you have to start completion: // Copyright 2023 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in
    
func TestCreateMultiValuedIndexHasBinaryCollation(t *testing.T) {
	store := testkit.CreateMockStore(t)
	tk := testkit.NewTestKit(t, store)

	tk.MustExec("create table test.t (pk varchar(4) primary key clustered, j json, str varchar(255), value int, key idx((cast(j as char(100) array)), str));")
	is := tk.Session().GetDomainInfoSchema().(infoschema.InfoSchema)
	require.NotNil(t, is)

	tbl, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t"))
	require.NoError(t, err)

	foundIndex := false
	for _, c := range tbl.Cols() {
		if c.Hidden {
			foundIndex = true
			require.True(t, c.FieldType.IsArray())
			require.Equal(t, c.FieldType.GetCharset(), "binary")
			require.Equal(t, c.FieldType.GetCollate(), "binary")
		}
	}
	require.True(t, foundIndex)
}