<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def check_for_valid_postback_actions(self, required_keys, post_params):
 """ checks if post_params contain required keys """

        for key in required_keys:
            if key not in post_params:
                return False
        return True