'Override for Property._check_property().
Raises:
InvalidPropertyError if no subproperty is specified or if something
is wrong with the subproperty.'

def _check_property(self, rest=None, require_indexed=True):

    if (not rest):
        raise InvalidPropertyError(('Structured    property    %s    requires    a    subproperty' % self._name))
    self._modelclass._check_properties([rest], require_indexed=require_indexed)
