<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def normalize_sequence(seq):
 """return normalized representation of sequence for hashing This really means ensuring that the sequence is represented as a binary blob and removing whitespace and asterisks and uppercasing. 'ACGT' 'ACGT' Traceback (most recent call last):
 RuntimeError: Normalized sequence contains non-alphabetic characters """


    nseq = re.sub(r"[\s\*]", "", seq).upper()
    m = re.search("[^A-Z]", nseq)
    if m:
        _logger.debug("Original sequence: " + seq)
        _logger.debug("Normalized sequence: " + nseq)
        _logger.debug("First non-[A-Z] at {}".format(m.start()))
        raise RuntimeError("Normalized sequence contains non-alphabetic characters")
    return nseq