text: // Task Part
  function askForNote(topic, callback){
      console.log('Friend received the call and told me to wait, until note not found');
      setTimeout(function(){
          console.log("note found after 2 hours");
          callback(null, {
              pdfNote: topic
          })
      }, 2000);
  };
  
  function printNote(pdfNote, callback){
      console.log('Note is in stationary');
      console.log('Shopkeeper promise to call me after finish printing');
      let electricity = true;
      if(electricity){
          setTimeout(function(){
              callback(null, {
                  print: pdfNote
              });
          }, 2000);
      } else {
          callback('no-electricity');
      }
  };
  
  function entertainment(callback){
      console.log('Entertainment started');
      setTimeout(function(){
          callback();
      }, 2000);
  };
  
  function servicing(callback){
      console.log('Bike is at servicing');
      setTimeout(function(){
          callback();
      }, 2000);
  };
  
  
  
  
  // Execution part
  console.log('Start preparation for the exam');
  console.log('Call the friend for the node');
  askForNote('JavaScript', function(err, done){
      if(err){
          console.log('Error getting note', err)
      } else {
          console.log('Success in getting note', done);
          console.log('note is in pdf now print note');
          printNote('pdfNote', function(err, done){
              if(err){
                  console.log('Printing failed', err);
              }else{
                  console.log('Printing completed >> ', done);
                  entertainment(function(){
                      console.log('Entertainment finished');
                      servicing(function(){
                          console.log('Bike servicing finished');
                          console.log('now start prepration');
                      })
                  })
              }
          });
          console.log('Meet friend');
          console.log('Had a coffee');
      }
  });
  console.log('clean room');
  console.log('prepare pen pencils papers');
  
  
  
  
  