code: function next( error, hash, i ) {
  		if ( error ) {
  			done( error );
  			return;
  		}
  		hashes[ i ] = hash;
  		if ( ++count === len ) {
  			done( null, hashes );
  		}
  	}
docs: FUNCTION: next( error, hash, i )
  Callback invoked after a page has been processed.
  
  @private
  @param {Object|null} error - error object
  @param {Object} hash - anagram hash
  @param {Number} i - page index