Asynchronously Reading From SSH Output

I'd like to write a function that takes a SSH session and runs a command, providing an io.Reader that reads its output as it is recieved.

package main
import (
	"golang.org/x/crypto/ssh"
	"io"
)
func StreamOutput(session *ssh.Session, command string) (output io.Reader, err error) {
	if session != nil {
		defer session.Close()
	}
	if err != nil {
		return output, err
	}
	// connect to both outputs
	outReader, err := session.StdoutPipe()
	if err != nil {
		return output, err
	}
	errReader, err := session.StderrPipe()
	if err != nil {
		return output, err
	}
	output = io.MultiReader(outReader, errReader)
	err = session.Start(command)
	// return the readers that are to be read from
	return output, err

When I test this code using an ioutil.ReadAll on output, however, it only prints the appropriate output intermittently, even after calling session.Wait(). Why might this be? Is there a better way to return the functions output (channels, perhaps?)? Thanks!

The problem was that I had the following code in my function:

if session != nil {
    defer session.Close()
}

That way, the output would only print if the command completed and sent back its stdout before the function returned (which was infrequent). I fixed my code simply by removing these lines.