code: protected void setup(Mapper.Context context) {
          Configuration conf = context.getConfiguration();
          extractor = new CooccurrenceExtractor(conf);
  
          // Set up the IteratorFactory properties           
          Properties props = new Properties();
          for (String property : ITERATOR_FACTORY_PROPERTIES) {
              String propVal = conf.get(property);
              if (propVal != null)
                  props.setProperty(property, propVal);
          }
          
          // Create the ResourceFinder that the IteratorFactory will use to find
          // the various files on HDFS
          ResourceFinder hadoopRf = null;
          try {
              hadoopRf = new HadoopResourceFinder(conf);
          } catch (IOException ioe) {
              throw new IOError(ioe);
          }
  
          // Set the IteratorFactory to locate the resources and then have it
          // reconfigure itself based on the user specified properties
          IteratorFactory.setResourceFinder(hadoopRf);        
          IteratorFactory.setProperties(props);
      }
docs: Initializes all the properties for this particular mapper.  This process
  includes setting up the window size and configuring how the input
  documents will be tokenized.