internal CAMLBooleanAnd(Expression leftNode, Expression rightNode)
     : base(leftNode, rightNode)
 {
 }
 internal CAMLBooleanOr(Expression leftExp, Expression rightExp)
     : base(leftExp, rightExp)
 {
 }
 public virtual BooleanOr CreateBooleanOr(Expression left, Expression right)
 {
     return new BooleanOr(left, right);
 }
 public virtual Where CreateWhere(Expression expressionExp)
 {
     return new Where(expressionExp);
 }
 public override BooleanOr CreateBooleanOr(Expression left, Expression right)
 {
     return new CAMLBooleanOr(left, right);
 }
 public override Where CreateWhere(Expression expressionExp)
 {
     return new CAMLWhere(expressionExp);
 }