Checks if a particular index is allocated.

    Args:
        entry_number (int): Index to verify

    Returns:
        bool: True if it is allocated, False otherwise.

def _entry_allocated_bitmap(self, entry_number):
    """Checks if a particular index is allocated.

    Args:
        entry_number (int): Index to verify

    Returns:
        bool: True if it is allocated, False otherwise.
    """
    index, offset = divmod(entry_number, 8)
    return bool(self._bitmap[index] & (1 << offset))