def read(self, file_des, num_bytes):
        """Read number of bytes from a file descriptor, returns bytes read.

        Args:
            file_des: An integer file descriptor for the file object requested.
            num_bytes: Number of bytes to read from file.

        Returns:
            Bytes read from file.

        Raises:
            OSError: bad file descriptor.
            TypeError: if file descriptor is not an integer.
        """
        file_handle = self.filesystem.get_open_file(file_des)
        file_handle.raw_io = True
        return file_handle.read(num_bytes)
Read number of bytes from a file descriptor, returns bytes read.

        Args:
            file_des: An integer file descriptor for the file object requested.
            num_bytes: Number of bytes to read from file.

        Returns:
            Bytes read from file.

        Raises:
            OSError: bad file descriptor.
            TypeError: if file descriptor is not an integer.