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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 to_bytes(s, encoding=None, errors='strict'):
 """Convert string to bytes."""

    encoding = encoding or 'utf-8'

    if is_unicode(s):
        return s.encode(encoding, errors)
    elif is_strlike(s):
        return s
    else:
        if six.PY2:
            return str(s)
        else:
            return str(s).encode(encoding, errors)