CreateQuery x (children 3)
 Identifier x
 Storage definition (children 2)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 2)
     Function tuple (alias a) (children 1)
      ExpressionList
     Function tuple (alias b) (children 1)
      ExpressionList
