public virtual void Visiting(SqlIsNullPredicate isNullPredicate)
 {
     isNullPredicate.LeftExpression.Accept(this);
     sqlBuilder.Append(" Is");
     if (isNullPredicate.Negative)
     {
         sqlBuilder.Append(" Not");
     }
     sqlBuilder.Append(" Null");
 }
 public virtual void Visited(SqlIsNullPredicate isNullPredicate)
 {
 }