CreateQuery t0 (children 3)
 Identifier t0
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration k0 (children 1)
    DataType String
   ColumnDeclaration v0 (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType String
 Storage definition (children 2)
  Function MergeTree (children 1)
   ExpressionList
  Identifier k0
