code: def test_array_longinit(self):
      Base = declarative_base()
  
      class A(Base):
          __tablename__ = "a"
          id = Column("id", Integer, primary_key=True)
          array = Column("_array", ARRAY(Integer), default=[])
          first = index_property("array", 0)
  
          fifth = index_property("array", 4)
  
      a1 = A(fifth=10)
      a2 = A(first=5)
  
      eq_(a1.array, [None, None, None, None, 10])
      eq_(a2.array, [5])
  
      assert_raises(IndexError, setattr, a2, "fifth", 10)
  
imports: import sqlalchemy
  from sqlalchemy import inspect
  from sqlalchemy import Integer
  from sqlalchemy import testing
  from sqlalchemy import Text
  from sqlalchemy.ext.indexable import index_property
  from sqlalchemy.orm import declarative_base
  from sqlalchemy.orm import Session
  from sqlalchemy.sql.sqltypes import ARRAY
  from sqlalchemy.sql.sqltypes import JSON
  from sqlalchemy.testing import assert_raises
  from sqlalchemy.testing import eq_
  from sqlalchemy.testing import fixtures
  from sqlalchemy.testing import in_
  from sqlalchemy.testing import is_
  from sqlalchemy.testing import ne_
  from sqlalchemy.testing import not_in
  from sqlalchemy.testing.entities import ComparableEntity
  from sqlalchemy.testing.schema import Column
label_desc: Use image node_id 2 for calling the IndexPropertyTest obj's underlying member method code with example usage: obj.test_array_longinit() without return types