astUnaryExpression(uNode, retArr) {
    const unaryResult = this.checkAndUpconvertBitwiseUnary(uNode, retArr);
    if (unaryResult) {
      return retArr;
    }

    if (uNode.prefix) {
      retArr.push(uNode.operator);
      this.astGeneric(uNode.argument, retArr);
    } else {
      this.astGeneric(uNode.argument, retArr);
      retArr.push(uNode.operator);
    }

    return retArr;
  }
@desc Parses the abstract syntax tree for *Unary* Expression
@param {Object} uNode - An ast Node
@param {Array} retArr - return array string
@returns {Array} the append retArr