public PatternGuardExpr(String namespace,String name,List<Expression> parameters,PatternExpr guardedPattern){
  super(namespace,name,parameters);
  this.guarded=new ArrayList<PatternExpr>();
  guarded.add(guardedPattern);
}

public PatternGuardExpr ( String namespace , String name , List < Expression > parameters , PatternExpr guardedPattern ) { super ( namespace , name , parameters ) ; this . guarded = new ArrayList < PatternExpr > ( ) ; guarded . add ( guardedPattern ) ; }
ctor - for use to create a pattern expression tree , without pattern child expression .
