// create a filter to remove records that don't meet the expression
Expression nullToFalse = Expressions.call( Functions.class, "falseIfNull", condition );
Expression not = Expressions.not( nullToFalse ); // matches #isRemove semantics in Filter
statements.add( Expressions.return_( null, not ) );
BlockStatement block = statements.toBlock();
String expression = Expressions.toString( block );
LOG.debug( "filter parameters: {}", incomingFields );
LOG.debug( "filter expression: {}", expression );