code: def get_sources(self, prefix=''):
          
          prefix = prefix.replace('-', '_')
          prefixed = '%s_sources' % prefix
  
          if prefixed in self.__cli:
              sources = self.__cli.get(prefixed)
              from_conf = False
          else:
              sources = self.__config.get(prefixed)
              from_conf = True
  
          if sources is None:
              return OrderedSet()
  
          sources = self.__resolve_patterns(sources, from_conf)
  
          prefixed = '%s_source_filters' % prefix
          if prefixed in self.__cli:
              filters = self.__cli.get(prefixed)
              from_conf = False
          else:
              filters = self.__config.get(prefixed)
              from_conf = True
  
          if filters is None:
              return sources
  
          sources -= self.__resolve_patterns(filters, from_conf)
  
          return sources
docs: Retrieve a set of absolute paths to sources, according to `prefix`
  
          `ConfigParser` will perform wildcard expansion and
          filtering.
  
          Args:
              prefix: str, the desired prefix.
  
          Returns:
              utils.utils.OrderedSet: The set of sources for the given
                  `prefix`.