new_contents: """Add an active field to Filter
  
  Revision ID: 2ea9623b21fa
  Revises: 18ebf3181f87
  Create Date: 2014-09-03 09:37:39.653039
  
  """
  
  # revision identifiers, used by Alembic.
  revision = '2ea9623b21fa'
  down_revision = '18ebf3181f87'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.add_column(
          'filters',
          sa.Column(
              'active',
              sa.Boolean(),
              default=True,
              nullable=False)
      )
  
  
  def downgrade():
      op.drop_column('filters', 'active')
  
subject: Add an alembic migration script adding the `active` field to the filters table