AlterQuery  test_table (children 2)
 ExpressionList (children 2)
  AlterCommand ADD_COLUMN (children 1)
   ColumnDeclaration struct.key (children 2)
    DataType Array (children 1)
     ExpressionList (children 1)
      DataType UInt8
    Literal Array_[UInt64_2, UInt64_4, UInt64_6]
  AlterCommand ADD_COLUMN (children 1)
   ColumnDeclaration struct.value (children 2)
    DataType Array (children 1)
     ExpressionList (children 1)
      DataType UInt8
    Identifier array
 Identifier test_table