new_contents: """max_{mode}_direct_path_duration
  these parameters are nullable. When null, there is no limit
  
  Revision ID: 204aae05372a
  Revises: 16d8bca1453b
  Create Date: 2019-03-25 15:49:29.025453
  
  """
  
  # revision identifiers, used by Alembic.
  revision = '204aae05372a'
  down_revision = '16d8bca1453b'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      ### commands auto generated by Alembic - please adjust! ###
      op.add_column(
          'instance',
          sa.Column('max_bike_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      op.add_column(
          'instance',
          sa.Column('max_bss_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      op.add_column(
          'instance',
          sa.Column('max_car_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      op.add_column(
          'instance',
          sa.Column('max_ridesharing_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      op.add_column(
          'instance',
          sa.Column('max_taxi_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      op.add_column(
          'instance',
          sa.Column('max_walking_direct_path_duration', sa.Integer(), server_default='86400', nullable=False),
      )
      ### end Alembic commands ###
  
  
  def downgrade():
      ### commands auto generated by Alembic - please adjust! ###
      op.drop_column('instance', 'max_walking_direct_path_duration')
      op.drop_column('instance', 'max_taxi_direct_path_duration')
      op.drop_column('instance', 'max_ridesharing_direct_path_duration')
      op.drop_column('instance', 'max_car_direct_path_duration')
      op.drop_column('instance', 'max_bss_direct_path_duration')
      op.drop_column('instance', 'max_bike_direct_path_duration')
      ### end Alembic commands ###
  
subject: add migration file