CreateQuery test (children 3)
 Identifier test
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration x (children 1)
    DataType Tuple (children 1)
     ExpressionList (children 2)
      NameTypePair a (children 1)
       DataType UInt64
      NameTypePair b (children 1)
       DataType String
 Storage definition (children 3)
  Function MergeTree
  Identifier x.b
  Set
