new_contents: """Discover HP Printers"""
  from . import MDNSDiscoverable
  
  
  class Discoverable(MDNSDiscoverable):
      """Support for the discovery of HP Printers"""
  
      def __init__(self, nd):
          """Initialize the HP Printer discovery"""
          super(Discoverable, self).__init__(nd, '_printer._tcp.local.')
  
      def get_entries(self):
          return self.find_by_device_name('HP ')
  
subject: add HP printers support (#185)