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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 iter_slices(string, slice_length):
 """Iterate over slices of a string."""

    pos = 0
    if slice_length is None or slice_length <= 0:
        slice_length = len(string)
    while pos < len(string):
        yield string[pos:pos + slice_length]
        pos += slice_length