question: public void toEPL ( StringWriter writer , Expression optionalWhereClause , EPStatementFormatter formatter ) { formatter . beginMerge ( writer ) ; writer . write ( "merge " ) ; writer . write ( windowName ) ; if ( optionalAsName != null ) { writer . write ( " as " ) ; writer . write ( optionalAsName ) ; } if ( optionalWhereClause != null ) { formatter . beginMergeWhere ( writer ) ; writer . write ( "where " ) ; optionalWhereClause . toEPL ( writer , ExpressionPrecedenceEnum . MINIMUM ) ; } for ( OnMergeMatchItem item : matchItems ) { item . toEPL ( writer , formatter ) ; } }
target:  Renders the clause in textual representation.