CSV::Parser#strip_value

# File tmp/rubies/ruby-3.0.5/lib/csv/parser.rb, line 1069
def strip_value(value)
  return value unless @strip
  return nil if value.nil?

  case @strip
  when String
    size = value.size
    while value.start_with?(@strip)
      size -= 1
      value = value[1, size]
    end
    while value.end_with?(@strip)
      size -= 1
      value = value[0, size]
    end
  else
    value.strip!
  end
  value
end