docs: def validate_args(self):
          """Input validation!"""
          def validate_name():
              allowed_re = '^[a-z](([a-z0-9_-]+)?([a-z0-9])?)?'
              assert isinstance(self.params['name'], basestring), (
                  'Name must be a string, not %s' % repr(self.params['name']))
              assert re.match(allowed_re, self.params['name']), (
                  'Invalid rule name: %s. Must match %s.' % (
                      repr(self.params['name']), repr(allowed_re)))
          validate_name()
  
          def validate_deps():
              if 'deps' in self.params:
                  assert type(self.params['deps']) in (type(None), list), (
                      'Deps must be a list, not %s' % repr(self.params['deps']))
          validate_deps()