'If include_needle is True, add its length to the result.
Returns None is needle can\'t be found.'

def searchBytesLength(self, needle, include_needle, start_address=0, end_address=None):

    pos = self.searchBytes(needle, start_address, end_address)
    if (pos is None):
        return None
    length = ((pos - start_address) // 8)
    if include_needle:
        length += len(needle)
    return length
