def do_move_to(self, element, decl, pseudo):
        """Implement move-to declaration."""
        target = serialize(decl.value).strip()
        step = self.state[self.state['current_step']]
        elem = self.current_target().tree

        #  Find if the current node already has a move, and remove it.
        actions = step['actions']
        for pos, action in enumerate(reversed(actions)):
            if action[0] == 'move' and action[1] == elem:
                target_index = - pos - 1
                actions[target_index:] = actions[target_index+1:]
                break

        _, valstep = self.lookup('pending', target)
        if not valstep:
            step['pending'][target] = [('move', elem)]
        else:
            self.state[valstep]['pending'][target].append(('move', elem))
Implement move-to declaration.