docs: def _findlinestarts(code):
    """Find the offsets in a byte code which are start of lines in the source.
  
    Generate pairs (offset, lineno) as described in Python/compile.c.
  
    Arguments:
      code: code object.
  
    Yields:
      Address and line number pairs.
    """
    byte_increments = [ord(c) for c in code.co_lnotab[0::2]]
    line_increments = [ord(c) for c in code.co_lnotab[1::2]]
  
    lastlineno = None
    lineno = code.co_firstlineno
    addr = 0
    for byte_incr, line_incr in zip(byte_increments, line_increments):
      if byte_incr:
        if lineno != lastlineno:
          yield (addr, lineno)
          lastlineno = lineno
        addr += byte_incr
      lineno += line_incr
    if lineno != lastlineno:
      yield (addr, lineno)