SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier json.a
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 1)
       Identifier json.b
   Function has (children 1)
    ExpressionList (children 2)
     Identifier json.a
     Literal UInt64_2
