Psych::Visitors::ToRuby#deduplicate

# File tmp/rubies/ruby-3.3.0/ext/psych/lib/psych/visitors/to_ruby.rb, line 385
def deduplicate key
  if key.is_a?(String)
    # It is important to untaint the string, otherwise it won't
    # be deduplicated into an fstring, but simply frozen.
    -(key.untaint)
  else
    key
  end
end