CreateQuery test_serialization (children 3)
 Identifier test_serialization
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration id (children 1)
    DataType UInt64
   ColumnDeclaration text (children 1)
    DataType AggregateFunction (children 1)
     ExpressionList (children 2)
      Identifier groupConcat
      DataType String
 Storage definition (children 2)
  Function AggregatingMergeTree (children 1)
   ExpressionList
  Identifier id
