code: def test_dataclass_eventual():
      @serde.dataclass
      class X:
          y: int = serde.EVENTUAL
  
          def __eventually__(self, y):
              y.set_default(3)
  
      x1 = X(y=1)
      assert x1.y == 1
  
      x2 = X()
      assert x2.y == 3
  
file_path: gluonts/test/core/test_serde_dataclass.py
imports: from typing import List
  from gluonts.core import serde
  from gluonts.pydantic import BaseModel
label_desc: Use image node_id 4 for calling a global function with example usage: test_dataclass_eventual() without return types