code: def test_straight_remove(self):
      User, Address = self.classes.User, self.classes.Address
  
      u1 = User()
  
      a1 = Address(email_address="1")
      a2 = Address(email_address="2")
      a3 = Address(email_address="3")
      u1.addresses.append(a1)
      u1.addresses.append(a2)
      u1.addresses.append(a3)
  
      del u1.addresses[2]
  
      assert a3.user is None
      eq_(u1.addresses, [a1, a2])
  
imports: from sqlalchemy import testing
  from sqlalchemy import text
  from sqlalchemy.orm import attributes
  from sqlalchemy.orm import backref
  from sqlalchemy.orm import relationship
  from sqlalchemy.orm import Session
  from sqlalchemy.testing import eq_
  from sqlalchemy.testing import is_
  from sqlalchemy.testing.fixtures import fixture_session
  from test.orm import _fixtures
label_desc: Use image node_id 16 for calling the O2MCollectionTest obj's underlying member method code with example usage: obj.test_straight_remove() without return types