CreateQuery test_dictionary_nullable (children 3)
 Identifier test_dictionary_nullable
 ExpressionList (children 2)
  DictionaryAttributeDeclaration id (children 1)
   DataType UInt64
  DictionaryAttributeDeclaration value (children 1)
   DataType Nullable (children 1)
    ExpressionList (children 1)
     DataType String
 Dictionary definition (children 3)
  ExpressionList (children 1)
   Identifier id
  FunctionWithKeyValueArguments  clickhouse (children 1)
   ExpressionList (children 1)
    pair (children 1)
     Literal \'dictionary_nullable_source_table\'
  Dictionary layout (children 1)
   ExpressionList
