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: zpages_test.go
    path of file: ./repos/opencensus-go/zpages
    
    the code of the file until where you have to start completion: // Copyright 2017, OpenCensus 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, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package zpages

import (
	"bytes"
	"reflect"
	"testing"
	"time"

	"fmt"
	"net/http"
	"net/http/httptest"

	"go.opencensus.io/trace"
)

var (
	tid  = trace.TraceID{1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 4, 8, 16, 32, 64, 128}
	sid  = trace.SpanID{1, 2, 4, 8, 16, 32, 64, 128}
	sid2 = trace.SpanID{0, 3, 5, 9, 17, 33, 65, 129}
)

func TestTraceRows(t *testing.T) {
	now := time.Now()
	later := now.Add(2 * time.Second)
	data := traceDataFromSpans("foo", []*trace.SpanData{{
		SpanContext:  trace.SpanContext{TraceID: tid, SpanID: sid},
		ParentSpanID: sid2,
		Name:         "foo",
		StartTime:    now,
		EndTime:      later,
		Attributes:   map[string]interface{}{"stringkey": "stringvalue", "intkey": 42, "boolkey": true},
		Annotations: []trace.Annotation{
			{Time: now.Add(time.Millisecond), Message: "hello, world", Attributes: map[string]interface{}{"foo": "bar"}},
			{Time: now.Add(1500 * time.Millisecond), Message: "hello, world"},
		},
		MessageEvents: []trace.MessageEvent{
			{Time: now, EventType: 2, MessageID: 0x3, UncompressedByteSize: 0x190, CompressedByteSize: 0x12c},
			{Time: later, EventType: 1, MessageID: 0x1, UncompressedByteSize: 0xc8, CompressedByteSize: 0x64},
		},
		Status: trace.Status{
			Code:    1,
			Message: "d'oh!",
		},
	}})
	fakeTime := "2006/01/02-15:04:05.123456"
	for i := range data.Rows {
		data.Rows[i].Fields[0] = fakeTime
	}
	if want := (traceData{
		Name: "foo",
		Num:  1,
		Rows: []traceRow{
			{Fields: [3]string{fakeTime, "    2.000000", ""}, SpanContext: trace.SpanContext{TraceID: tid, SpanID: sid}, ParentSpanID: sid2},
			{Fields: [3]string{fakeTime, "", `Status{canonicalCode=CANCELLED, descrip
    
func TestTraceRows(t *testing.T) {
	now := time.Now()
	later := now.Add(2 * time.Second)
	data := traceDataFromSpans("foo", []*trace.SpanData{{
		SpanContext:  trace.SpanContext{TraceID: tid, SpanID: sid},
		ParentSpanID: sid2,
		Name:         "foo",
		StartTime:    now,
		EndTime:      later,
		Attributes:   map[string]interface{}{"stringkey": "stringvalue", "intkey": 42, "boolkey": true},
		Annotations: []trace.Annotation{
			{Time: now.Add(time.Millisecond), Message: "hello, world", Attributes: map[string]interface{}{"foo": "bar"}},
			{Time: now.Add(1500 * time.Millisecond), Message: "hello, world"},
		},
		MessageEvents: []trace.MessageEvent{
			{Time: now, EventType: 2, MessageID: 0x3, UncompressedByteSize: 0x190, CompressedByteSize: 0x12c},
			{Time: later, EventType: 1, MessageID: 0x1, UncompressedByteSize: 0xc8, CompressedByteSize: 0x64},
		},
		Status: trace.Status{
			Code:    1,
			Message: "d'oh!",
		},
	}})
	fakeTime := "2006/01/02-15:04:05.123456"
	for i := range data.Rows {
		data.Rows[i].Fields[0] = fakeTime
	}
	if want := (traceData{
		Name: "foo",
		Num:  1,
		Rows: []traceRow{
			{Fields: [3]string{fakeTime, "    2.000000", ""}, SpanContext: trace.SpanContext{TraceID: tid, SpanID: sid}, ParentSpanID: sid2},
			{Fields: [3]string{fakeTime, "", `Status{canonicalCode=CANCELLED, description="d'oh!"}`}},
			{Fields: [3]string{fakeTime, "", `Attributes:{boolkey=true, intkey=42, stringkey="stringvalue"}`}},
			{Fields: [3]string{fakeTime, "     .     0", "received message [400 bytes, 300 compressed bytes]"}},
			{Fields: [3]string{fakeTime, "     .  1000", `hello, world  Attributes:{foo="bar"}`}},
			{Fields: [3]string{fakeTime, "    1.499000", "hello, world"}},
			{Fields: [3]string{fakeTime, "     .500000", "sent message [200 bytes, 100 compressed bytes]"}}}}); !reflect.DeepEqual(data, want) {
		t.Errorf("traceRows: got %v want %v\n", data, want)
	}

	var buf bytes.Buffer
	writeTextTraces(&buf, data)
	if want := `When                       Elapsed(s)   Type
2006/01/02-15:04:05.123456     2.000000 trace_id: 01020304050607080102040810204080 span_id: 0102040810204080 parent_span_id: 0003050911214181
2006/01/02-15:04:05.123456              Status{canonicalCode=CANCELLED, description="d'oh!"}
2006/01/02-15:04:05.123456              Attributes:{boolkey=true, intkey=42, stringkey="stringvalue"}
2006/01/02-15:04:05.123456      .     0 received message [400 bytes, 300 compressed bytes]
2006/01/02-15:04:05.123456      .  1000 hello, world  Attributes:{foo="bar"}
2006/01/02-15:04:05.123456     1.499000 hello, world
2006/01/02-15:04:05.123456      .500000 sent message [200 bytes, 100 compressed bytes]
`; buf.String() != want {
		t.Errorf("writeTextTraces: got %q want %q\n", buf.String(), want)
	}
}