Unicode.Property.other_grapheme_extend
You're seeing just the function
other_grapheme_extend, go back to Unicode.Property module for more information.
Returns :other_grapheme_extend or nil indicating
if the codepoint or string has the property
:other_grapheme_extend.
For string parameters, all codepoints in
the string must have the :other_grapheme_extend
property in order for the result to :other_grapheme_extend.