new_contents: """empty message
  
  Revision ID: c3500625bed8
  Revises: 3dcc171e7253
  Create Date: 2017-02-21 16:08:43.397517
  
  """
  from alembic import op
  import sqlalchemy as sa
  from sqlalchemy.dialects import mysql
  
  # revision identifiers, used by Alembic.
  revision = 'c3500625bed8'
  down_revision = '3dcc171e7253'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      op.rename_table('blob', 'instance')
  
      op.alter_column('log', 'blob_id', new_column_name='instance_id', existing_type=sa.BigInteger())
      op.alter_column('version', 'blob_id', new_column_name='instance_id', existing_type=sa.BigInteger())
      op.alter_column('tag', 'blob_id', new_column_name='instance_id', existing_type=sa.BigInteger())
  
  def downgrade():
      op.rename_table('instance', 'blob')
  
      op.alter_column('log', 'instance_id', new_column_name='blob_id', existing_type=sa.BigInteger())
      op.alter_column('version', 'instance_id', new_column_name='blob_id', existing_type=sa.BigInteger())
      op.alter_column('tag', 'instance_id', new_column_name='blob_id', existing_type=sa.BigInteger())
  
subject: Add the migration. Oops.