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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def millis_interval(start, end):
 """start and end are datetime instances"""

    diff = end - start
    millis = diff.days * 24 * 60 * 60 * 1000
    millis += diff.seconds * 1000
    millis += diff.microseconds / 1000
    return millis