title: Pig Latin Remove Tuple in Data Bag
body: <p>Here is my code leading up to my issue:</p>
  
  <pre><code> a = LOAD 'tellers' using TextLoader() AS line;
   # convert a to charrarry
   b = foreach a generate (chararray)line;  
   # run through my UDF to create tuples
   c = foreach b generate myudfs.TellerParser5(line);  # ({(20),(5),(5),(10)(1),(1),(1),(1),(1),(5),(10),(10),(10)})....
   d = foreach c generate flatten(number); 
   e = group d by number; #{group: chararray,d: {(number: chararray)}}
   f = foreach e generate group, COUNT(d);  # f: {group: chararray,long}
  </code></pre>
  
  <p>In databag f, I have an empty tuple (,1) I'd like to filter/remove.  </p>
  
  <pre><code> dump f;
   (,1)
   (1,97)
   (5,49)
   (10,87)
   (20,24)
  
   describe f;
   f: {group: chararray,long}
  </code></pre>
  
  <p>I've tried this with no success (makes no change):</p>
  
  <pre><code> remove_tuple = filter f BY group is not null; 
  </code></pre>