code: def num_available(self, work_spec_name):
          '''Get the number of available work units for some work spec.
  
          These are work units that could be returned by :meth:`get_work`:
          they are not complete, not currently executing, and not blocked
          on some other work unit.
  
          '''
          return self.registry.len(WORK_UNITS_ + work_spec_name,
                                   priority_max=time.time()f num_available(self, work_spec_name):
          '''Get the number of available work units for some work spec.
  
          These are work units that could be returned by :meth:`get_work`:
          they are not complete, not currently executing, and not blocked
          on some other work unit.
  
          '''
          return self.registry.len(WORK_UNITS_ + work_spec_name,
                                   priority_max=time.time())
docs: Get the number of available work units for some work spec.
  
          These are work units that could be returned by :meth:`get_work`:
          they are not complete, not currently executing, and not blocked
          on some other work unit.