CreateQuery test (children 3)
 Identifier test
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration a (children 1)
    DataType String
   ColumnDeclaration alias_col_a (children 2)
    DataType String
    Identifier a
 Storage definition (children 2)
  Function MergeTree
  Identifier a
