SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function caseWithExpression (children 1)
     ExpressionList (children 6)
      Function plus (children 1)
       ExpressionList (children 2)
        Identifier a
        Identifier b
      Identifier c
      Literal \'c\'
      Identifier d
      Literal \'d\'
      Literal NULL
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test1
