title: How to get the PrinterDiscoverySession when using the printer in android 4.4
body: <p>I am recently using the Printing Framework in Android 4.4, now I have a demand to get the printer's information which can be used in the Mobile phone or tablet. </p>
  
  <p>I found the <a href="https://developer.android.com/reference/android/printservice/PrinterDiscoverySession.html" rel="nofollow">PrinterDiscoverySession</a> class contains the printer's information. But how can I get the instance of the PrinterDiscoverySession class?</p>