SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Function arrayJoin (alias field) (children 1)
     ExpressionList (children 1)
      Literal Array_[\'a\', \'a\', \'b\', \'b\']
   ExpressionList (children 2)
    Identifier field
    Function count (children 1)
     ExpressionList
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier field
   Literal UInt64_1
