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: reader_test.go
    path of file: ./repos/poseidon/builder/docformat/src/github.com/mreiferson/go-snappystream
    
    the code of the file until where you have to start completion: package snappystream

import (
	"bytes"
	"crypto/rand"
	"fmt"
	"io"
	"io/ioutil"
	"strings"
	"testing"

	"github.com/mreiferson/go-snappystream/snappy-go"
)

// This test checks t
    
func compressedChunkGreaterN(t *testing.T, n int) []byte {
	decoded := make([]byte, n)
	var numTries int
	var encoded []byte
	for len(encoded) <= n && numTries < 3 {
		numTries++
		nrd, err := io.ReadFull(rand.Reader, decoded)
		if err != nil {
			t.Errorf("crypto/rand: %v", err)
			return nil
		}
		if nrd != n {
			t.Errorf("crypto/rand: bad read (%d bytes)", nrd)
			return nil
		}
		encoded, err = snappy.Encode(encoded[:cap(encoded)], decoded)
		if err != nil {
			t.Errorf("snappy: %v", err)
			return nil
		}
	}
	if len(encoded) <= n {
		t.Error(errNotEnoughEntropy)
		return nil
	}

	return compressedChunk(t, decoded)
}