CreateQuery t1 (children 3)
 Identifier t1
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration x (children 1)
    DataType UInt64
   ColumnDeclaration y (children 1)
    DataType Tuple (children 1)
     ExpressionList (children 2)
      DataType UInt64
      DataType UInt64
 Storage definition (children 2)
  Function MergeTree
  Identifier x
