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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 _find_furthest_new_line(read_buffer):
 """Return -1 if read_buffer does not contain new line otherwise the position of the rightmost newline. Args: read_buffer (bytestring) Returns: int: The right most position of new line character in read_buffer if found, else -1 """

    new_line_positions = [read_buffer.rfind(n) for n in new_lines_bytes]
    return max(new_line_positions)