CreateQuery test (children 3)
 Identifier test
 Columns definition (children 1)
  ExpressionList (children 4)
   ColumnDeclaration a (children 1)
    DataType Date
   ColumnDeclaration b (children 1)
    DataType UInt32
   ColumnDeclaration c (children 1)
    DataType UInt64
   ColumnDeclaration p (children 1)
    DataType Nested (children 1)
     ExpressionList (children 2)
      NameTypePair at1 (children 1)
       DataType String
      NameTypePair at2 (children 1)
       DataType String
 Storage definition (children 4)
  Function MergeTree (children 1)
   ExpressionList
  Identifier a
  Identifier b
  Set