old_contents: from sqlalchemy import MetaData, Table, Column
  
  from sqlalchemy.types import TEXT
  
  
  def upgrade(migrate_engine):
      meta = MetaData(bind=migrate_engine)
  
      table = Table('user', meta, autoload=True)
      col = table.c.optional_attributes
      if col.type != TEXT:
          col.alter(type=TEXT)
  
new_contents: from sqlalchemy import MetaData, Table
  
  from sqlalchemy.types import TEXT
  
  
  def upgrade(migrate_engine):
      meta = MetaData(bind=migrate_engine)
  
      table = Table('user', meta, autoload=True)
      col = table.c.optional_attributes
      if col.type != TEXT:
          col.alter(type=TEXT)
  
subject: Remove useless import