CreateQuery testing (children 3)
 Identifier testing
 Columns definition (children 2)
  ExpressionList (children 4)
   ColumnDeclaration a (children 1)
    DataType String
   ColumnDeclaration b (children 1)
    DataType String
   ColumnDeclaration c (children 1)
    DataType String
   ColumnDeclaration d (children 1)
    DataType String
  ExpressionList (children 1)
   Projection (children 1)
    ProjectionSelectQuery (children 2)
     ExpressionList (children 2)
      Identifier b
      Identifier c
     Identifier d
 Storage definition (children 4)
  Function MergeTree (children 1)
   ExpressionList
  Identifier a
  Function tuple (children 1)
   ExpressionList (children 2)
    Identifier a
    Identifier b
  Set
