strwrap_ctl(u21, 5, carry = paste0(open, "\033[33m"))

# Adjacent URLs with same ID should be merged

# Abutting URLs with no intervening content: last wins

# corner cases with bad/non-portable bytes

Argument `x` contains a CSI SGR sequence or OSC hyperlink with invalid substrings at index [2], see `?unhandled_ctl`; you can use `warn=FALSE` to turn off these warnings.

Argument `x` contains a CSI SGR sequence or OSC hyperlink with invalid substrings at index [3], see `?unhandled_ctl`; you can use `warn=FALSE` to turn off these warnings.

Warning in substr_ctl_internal(x, start = start, stop = stop, type.int = TYPE.INT,  :
  Argument `x` contains a CSI SGR sequence or OSC hyperlink with invalid substrings at index [1], see `?unhandled_ctl`; you can use `warn=FALSE` to turn off these warnings.
Warning in substr_ctl_internal(x, start = start, stop = stop, type.int = TYPE.INT,  :
  Argument `x` contains a CSI SGR sequence or OSC hyperlink with invalid substrings at index [2], see `?unhandled_ctl`; you can use `warn=FALSE` to turn off these warnings.
Warning in substr_ctl_internal(x, start = start, stop = stop, type.int = TYPE.INT,  :
  Argument `x` contains a CSI SGR sequence or OSC hyperlink with invalid substrings at index [3], see `?unhandled_ctl`; you can use `warn=FALSE` to turn off these warnings.

Error in substr_ctl_internal(x, start = start, stop = stop, type.int = TYPE.INT,  : 
  Argument `x` contains an illegal non-ASCII byte at index [1], see `?unhandled_ctl`.

<a href='https://x.yz'>This is a link</a>

[1] "<a href='https://x.yz'>This is a link</a>"

A<span style='background-color: #0000BB;'>B</span><a href='x.y'><span style='background-color: #0000BB;'>C</span></a><span style='color: #BBBB00; background-color: #0000BB;'>D</span>

[1] "A<span style='background-color: #0000BB;'>B</span><a href='x.y'><span style='background-color: #0000BB;'>C</span></a><span style='color: #BBBB00; background-color: #0000BB;'>D</span>"

A<span style='background-color: #0000BB;'>B</span><a href='x.y'><span style='background-color: #0000BB;'>C</span></a><a href='w.z'><span style='color: #BBBB00; background-color: #0000BB;'>D</span></a>