code: def test_time_invalid_string(self):
      assert_raises_message(
          ValueError,
          "Invalid isoformat string: '5:a'",
          self.module.str_to_time,
          "5:a",
      )
  
imports: import datetime
  import re
  from types import MappingProxyType
  from sqlalchemy import exc
  from sqlalchemy.engine import processors
  from sqlalchemy.testing import assert_raises_message
  from sqlalchemy.testing import eq_
  from sqlalchemy.testing import expect_raises_message
  from sqlalchemy.testing import fixtures
  from sqlalchemy.util import immutabledict
label_desc: Use image node_id 7 for calling the _DateProcessorTest obj's underlying member method code with example usage: obj.test_time_invalid_string() without return types