CreateQuery tab (children 4)
 Identifier tab
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration x (children 1)
    DataType String
 Storage definition (children 2)
  Function MergeTree
  Identifier x
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 1)
     Literal \'Hello\'