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: echotest.go
    path of file: ./repos/cockroach/pkg/testutils/echotest
    
    the code of the file until where you have to start completion: // Copyright 2022 The Cockroach Authors.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this soft
    
func Require(t *testing.T, act, path string) {
	t.Helper()
	var ran bool
	datadriven.RunTest(t, path, func(t *testing.T, d *datadriven.TestData) string {
		t.Helper()
		if d.Cmd != "echo" {
			return "only 'echo' is supported"
		}
		ran = true
		return act
	})
	if !ran {
		// Guard against a possible error in which the file is created, then datadriven
		// is invoked with -rewrite to seed it (which it does not do, since there is
		// no directive in the file), and then also the tests pass despite not checking
		// anything.
		t.Errorf("no tests run for %s, is the file empty?", path)
	}
}