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: pemfile_provider_test.go
    path of file: ./repos/sharingan/grpc-server/v1.33.2/security/advancedtls
    
    the code of the file until where you have to start completion: /*
 *
 * Copyright 2020 gRPC 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 
    
func (s) TestNewPEMFileProvider(t *testing.T) {
	tests := []struct {
		desc      string
		options   PEMFileProviderOptions
		certFile  string
		keyFile   string
		trustFile string
		wantError bool
	}{
		{
			desc:      "Expect error if no credential files specified",
			options:   PEMFileProviderOptions{},
			wantError: true,
		},
		{
			desc: "Expect error if only certFile is specified",
			options: PEMFileProviderOptions{
				CertFile: testdata.Path("client_cert_1.pem"),
			},
			wantError: true,
		},
		{
			desc: "Should be good if only identity key cert pairs are specified",
			options: PEMFileProviderOptions{
				KeyFile:  testdata.Path("client_key_1.pem"),
				CertFile: testdata.Path("client_cert_1.pem"),
			},
			wantError: false,
		},
		{
			desc: "Should be good if only root certs are specified",
			options: PEMFileProviderOptions{
				TrustFile: testdata.Path("client_trust_cert_1.pem"),
			},
			wantError: false,
		},
		{
			desc: "Should be good if both identity pairs and root certs are specified",
			options: PEMFileProviderOptions{
				KeyFile:   testdata.Path("client_key_1.pem"),
				CertFile:  testdata.Path("client_cert_1.pem"),
				TrustFile: testdata.Path("client_trust_cert_1.pem"),
			},
			wantError: false,
		},
	}
	for _, test := range tests {
		t.Run(test.desc, func(t *testing.T) {
			provider, err := NewPEMFileProvider(test.options)
			if (err != nil) != test.wantError {
				t.Fatalf("NewPEMFileProvider(%v) = %v, want %v", test.options, err, test.wantError)
			}
			if err != nil {
				return
			}
			provider.Close()
		})
	}

}