CreateQuery test (children 3)
 Identifier test
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration val (children 1)
    DataType LowCardinality (children 1)
     ExpressionList (children 1)
      DataType Nullable (children 1)
       ExpressionList (children 1)
        DataType String
 Storage definition (children 3)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList
  Set
