old_contents: class Library:
      """This class represents a simaris target and is initialized with
      data in JSON format
  
      """
  
      def __init__(self, data):
          self.target          = data['CurrentTarget']['EnemyType']
          self.scans           = data['CurrentTarget']['PersonalScansRequired']
          self.progress        = data['CurrentTarget']['ProgressPercent']
  
      def __str__(self):
          """Returns a string with all the information about this alert
  
          """
  
          library_string = ('Target: {0}\n'
                         'Scans needed: {1}\n'
                         'Progress: {2:.2f}%'
                         )
  
          return library_string.format(self.target, self.scans,
                                    self.progress)
new_contents: class Library:
      """This class represents a simaris target and is initialized with
      data in JSON format
  
      """
  
      def __init__(self, data):
          if 'CurrentTarget' in data:
              self.target          = data['CurrentTarget']['EnemyType']
              self.scans           = data['CurrentTarget']['PersonalScansRequired']
              self.progress        = data['CurrentTarget']['ProgressPercent']
              self.active = True
          else:
              self.active = False
  
      def __str__(self):
          """Returns a string with all the information about this alert
  
          """
          if not self.is_active():
              return None
  
          library_string = ('Target: {0}\n'
                         'Scans needed: {1}\n'
                         'Progress: {2:.2f}%'
                         )
  
          return library_string.format(self.target, self.scans,
                                    self.progress)
  
      def is_active(self):
          """ Returns True if there is a currently active target, False otherwise
  
          """
          return self.active
  
subject: Add is_active() method to the Library class