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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 parse_trailer(header):
 """Parse the "Trailer" header."""

    pos = 0
    names = []
    while pos < len(header):
        name, pos = expect_re(re_token, header, pos)
        if name:
            names.append(name)
        _, pos = accept_ws(header, pos)
        _, pos = expect_lit(',', header, pos)
        _, pos = accept_ws(header, pos)
    return names