--- !ruby/object:RI::MethodDescription 
aliases: []

block_params: 
comment: 
- !ruby/struct:SM::Flow::P 
  body: Run all the down steps for the migrations that have already been run.
- !ruby/struct:SM::Flow::P 
  body: has an optional argument 'level' which, if supplied, only performs the down migrations with a postion greater than the level.
full_name: DataMapper::MigrationRunner#migrate_down!
is_singleton: false
name: migrate_down!
params: (level = nil)
visibility: public
