public CSTUnaryExpressionCS(
     CSTOperatorCS operat,
     CSTOclExpressionCS expression)
 {
     this.operat     = operat;
     this.expression = expression;
 }
 public CSTBinaryExpressionCS(
     CSTOclExpressionCS leftExpression,
     CSTOperatorCS operat,
     CSTOclExpressionCS rightExpression)
 {
     this.leftExpression  = leftExpression;
     this.operat          = operat;
     this.rightExpression = rightExpression;
 }