public BinaryOperator(string Operator, Expression LeftOperand, Expression RightOperand)
 {
     this.Operator = Operator;
     this.LeftOperand = LeftOperand;
     this.RightOperand = RightOperand;
 }
 public If(Expression Condition, Expression Then)
 {
     this.Condition = Condition;
     this.Then = Then;
 }
 public While(Expression Condition, Expression Body)
 {
     this.Condition = Condition;
     this.Body = Body;
 }
 public If(Expression Condition, Expression Then, Expression Else)
 {
     this.Condition = Condition;
     this.Then = Then;
     this.Else = Else;
 }