old_contents: # https://www.w3.org/TR/filter-effects/#funcdef-brightness
  # https://www.w3.org/TR/SVG/filters.html#TransferFunctionElementAttributes
  
  from . import rgb_clamp
  
  
  def calc_rgb(rgb, ratio=100):
      r = float(ratio)
      return rgb_clamp(c * r / 100 for c in rgb)
  
new_contents: # https://www.w3.org/TR/filter-effects/#funcdef-brightness
  # https://www.w3.org/TR/SVG/filters.html#TransferFunctionElementAttributes
  
  from . import rgb_clamp
  
  
  def calc_rgb(rgb, ratio=100):
      """Return brightness adjusted RGB value of passed color.
  
      THe calculation is based on the definition found at
      https://www.w3.org/TR/filter-effects/#funcdef-brightness
      :param rgb: The Original RGB value before the adjustment.
      :type rgb: (int, int, int)
      :param ratio: Adjustment ratio in percentage [optional]
      :type ratio: float
      :return: Brightness adjusted RGB value
      :rtype: (int, int, int)
      """
      r = float(ratio)
      return rgb_clamp(c * r / 100 for c in rgb)
  
subject: add docstring to converters.brightness.calc_rgb()