new_contents: """empty message
  
  Revision ID: a65bdadbae2f
  Revises: e1ef93f40d3d
  Create Date: 2019-01-15 12:19:59.813805
  
  """
  from alembic import op
  import sqlalchemy as sa
  import sqlalchemy_utils
  from sqlalchemy.dialects import postgresql
  import sqlalchemy_utils
  import uuid
  
  # revision identifiers, used by Alembic.
  revision = 'a65bdadbae2f'
  down_revision = 'e1ef93f40d3d'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      # ### commands auto generated by Alembic - please adjust! ###
      op.create_table('metadata_descriptor',
      sa.Column('id', sqlalchemy_utils.types.uuid.UUIDType(binary=False), default=uuid.uuid4, nullable=False),
      sa.Column('created_at', sa.DateTime(), nullable=True),
      sa.Column('updated_at', sa.DateTime(), nullable=True),
      sa.Column('project_id', sqlalchemy_utils.types.uuid.UUIDType(binary=False), default=uuid.uuid4, nullable=False),
      sa.Column('entity_type', sa.String(length=60), nullable=False),
      sa.Column('name', sa.String(length=120), nullable=False),
      sa.Column('field_name', sa.String(length=120), nullable=False),
      sa.Column('choices', postgresql.JSONB(astext_type=sa.Text()), nullable=True),
      sa.ForeignKeyConstraint(['project_id'], ['project.id'], ),
      sa.PrimaryKeyConstraint('id'),
      sa.UniqueConstraint('project_id', 'entity_type', 'name', name='metadata_descriptor_uc')
      )
      op.create_index(op.f('ix_metadata_descriptor_entity_type'), 'metadata_descriptor', ['entity_type'], unique=False)
      op.create_index(op.f('ix_metadata_descriptor_project_id'), 'metadata_descriptor', ['project_id'], unique=False)
      # ### end Alembic commands ###
  
  
  def downgrade():
      # ### commands auto generated by Alembic - please adjust! ###
      op.drop_index(op.f('ix_metadata_descriptor_project_id'), table_name='metadata_descriptor')
      op.drop_index(op.f('ix_metadata_descriptor_entity_type'), table_name='metadata_descriptor')
      op.drop_table('metadata_descriptor')
      # ### end Alembic commands ###
  
subject: Add migration file for metadata descriptor