CreateQuery t1 (children 3)
 Identifier t1
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration id (children 1)
    DataType String
   ColumnDeclaration val (children 1)
    DataType String
 Storage definition (children 2)
  Function MergeTree (children 1)
   ExpressionList
  Identifier id
