code: def test_alter_column_comment(self):
      m1 = MetaData()
      m2 = MetaData()
  
      Table(
          "some_table",
          m1,
          Column("test", String(10), primary_key=True),
          Column("amount", Float, comment="the amount"),
      )
  
      Table(
          "some_table",
          m2,
          Column("test", String(10), primary_key=True),
          Column("amount", Float, comment="the adjusted amount"),
      )
  
      diffs = self._fixture(m1, m2)
  
      eq_(
          diffs,
          [
              [
                  (
                      "modify_comment",
                      None,
                      "some_table",
                      "amount",
                      {
                          "existing_nullable": True,
                          "existing_type": mock.ANY,
                          "existing_server_default": False,
                      },
                      "the amount",
                      "the adjusted amount",
                  )
              ]
          ],
      )
  
file_path: alembic/alembic/testing/suite/test_autogen_comments.py
imports: from sqlalchemy import Column
  from sqlalchemy import Float
  from sqlalchemy import MetaData
  from sqlalchemy import String
  from sqlalchemy import Table
  from ._autogen_fixtures import AutogenFixtureTest
  from ...testing import eq_
  from ...testing import mock
  from ...testing import TestBase
label_desc: Use image node_id 8 for calling the AutogenerateCommentsTest obj's underlying member method code with example usage: obj.test_alter_column_comment() without return types