def apply(patch)
      @db << patch.content
      register(patch)
    rescue Sequel::Error => ex
      raise Sequel::Error,
            "Failed to apply patch #{patch.full_filename}: #{ex}"
    end
def apply(patch)
      @db << patch.content
      register(patch)
    rescue Sequel::Error => ex
      raise Sequel::Error,
            "Failed to apply patch #{patch.full_filename}: #{ex}"
    end
Applies a patch (a Patch object).