如何使用Octokit gem获取Github文件的最后更新日期？

Question

我使用Octokit gem使用以下命令访问文件的内容：

 package com.backendless.chat.messaging;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.backendless.Backendless;
import com.backendless.services.messaging.MessageStatus;
import com.backendless.messaging.PublishOptions;
import com.backendless.services.messaging.PublishStatusEnum;

public class AcceptChatActivity extends Activity
{
private Button acceptButton, declineButton;
private TextView chatInvitationTextView;

private PublishOptions publishOptions;
private String subtopic;
private String companionNickname;

@Override
public void onCreate( Bundle savedInstanceState )
{
super.onCreate( savedInstanceState );
setContentView( R.layout.activity_accept_chat);

Intent currentIntent = getIntent();
subtopic = currentIntent.getStringExtra( "subtopic" );
companionNickname = subtopic.split( "_" )[ 0 ];

initUI();

Backendless.setUrl( Defaults.SERVER_URL );
Backendless.initApp( this, Defaults.APPLICATION_ID, Defaults.SECRET_KEY, Defaults.VERSION );

publishOptions = new PublishOptions();
publishOptions.setSubtopic( subtopic );
}

private void initUI()
{
acceptButton = (Button) findViewById( R.id.acceptButton );
declineButton = (Button) findViewById( R.id.declineButton );
chatInvitationTextView = (TextView) findViewById( R.id.chatInvitationText );

chatInvitationTextView.setText( String.format( getResources().getString( R.string.chat_invitation_message ), companionNickname ) );


 acceptButton.setOnClickListener( new View.OnClickListener()
 {
  @Override
  public void onClick( View v )
  {
    onAccept();
  }
  } );

declineButton.setOnClickListener( new View.OnClickListener()
{
  @Override
  public void onClick( View v )
  {
    onDecline();
  }
 } );
}

 private void onAccept()
{
  Intent nextIntent = new Intent( this, ChooseNicknameActivity.class );
 nextIntent.putExtra( "owner", false );
 nextIntent.putExtra( "subtopic", subtopic );
nextIntent.putExtra( "companionNickname", companionNickname );
startActivity( nextIntent );
finish();
} 

 private void onDecline()
 {
 Backendless.Messaging.publish( (Object)    
DefaultMessages.DECLINE_CHAT_MESSAGE, publishOptions, new       
DefaultCallback<MessageStatus>( this )
 {
  @Override
  public void handleResponse( MessageStatus response )
  {
    super.handleResponse( response );
    if( response.getStatus() == PublishStatusEnum.SCHEDULED )
    {
      finish();
    }
    else
    {
      Toast.makeText( AcceptChatActivity.this, response.getStatus().toString(), Toast.LENGTH_SHORT ).show();
    }
  }
} );
}
}

适用于获取内容。我的问题是如何获取该文件的最后更新日期和时间戳？