Refs #2017: add todo's

lib/pipeline/documentSources/FilterBaseDocumentSource.js

@@ -18,6 +18,9 @@ var FilterBaseDocumentSource = module.exports = (function(){
 		this.pCurrent = null;
 	}, base = require('./DocumentSource'), proto = klass.prototype = Object.create(base.prototype, {constructor:{value:klass}});
 
+	//! @todo Need to implement coalesce()
+	//! @todo Need to implement optimize()
+
 	/**
 	 * Find the next acceptable source document, if there are any left.
 	 *