def max_line_length(text, separator)
      lines = text.split(separator, -1)
      display_width(lines.max_by { |line| display_width(line) } || '')
    end
def max_line_length(text, separator)
      lines = text.split(separator, -1)
      display_width(lines.max_by { |line| display_width(line) } || '')
    end
Determine maximum length for all multiline content

 @param [String] text
 @param [String] separator

 @return [Integer]

 @api private