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: pubkeypin_test.go
    path of file: ./repos/openyurt/pkg/util/pubkeypin
    
    the code of the file until where you have to start completion: /*
Copyright 2017 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, eith
    
func testCert(t *testing.T, pemString string) *x509.Certificate {
	// Decode the example certificate from a PEM file into a PEM block
	pemBlock, _ := pem.Decode([]byte(pemString))
	if pemBlock == nil {
		t.Fatal("failed to parse test certificate PEM")
		return nil
	}

	// Parse the PEM block into an x509.Certificate
	result, err := x509.ParseCertificate(pemBlock.Bytes)
	if err != nil {
		t.Fatalf("failed to parse test certificate: %v", err)
		return nil
	}
	return result
}