CreateQuery nested (children 3)
 Identifier nested
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration x (children 1)
    DataType UInt64
   ColumnDeclaration filter (children 1)
    DataType UInt8
   ColumnDeclaration n (children 1)
    DataType Nested (children 1)
     ExpressionList (children 1)
      NameTypePair a (children 1)
       DataType UInt64
 Storage definition (children 3)
  Function MergeTree
  Identifier x
  Set