def is_extent_valid(self, start_time, duration, flag=None):
        """Check if the duration contains any non-valid frames

        Parameters
        ----------
        start_time: int
            Beginning of the duration to check in gps seconds
        duration: int
            Number of seconds after the start_time to check
        flag: str, optional
            Override the default valid mask with a user defined mask.

        Returns
        -------
        status: boolean
            Returns True if all of the status information if valid,
            False if any is not.
        """
        sr = self.raw_buffer.sample_rate
        s = int((start_time - self.raw_buffer.start_time) * sr)
        e = s + int(duration * sr) + 1
        data = self.raw_buffer[s:e]
        return self.check_valid(data, flag=flag)
Check if the duration contains any non-valid frames

        Parameters
        ----------
        start_time: int
            Beginning of the duration to check in gps seconds
        duration: int
            Number of seconds after the start_time to check
        flag: str, optional
            Override the default valid mask with a user defined mask.

        Returns
        -------
        status: boolean
            Returns True if all of the status information if valid,
            False if any is not.