class HTTP::Headers

def [](name)

Returns:
  • (Array) - if header has more than one value
  • (String) - if header has exactly one value
  • (nil) - if header was not set 
def [](name)
  values = get(name)
  case values.count
  when 0 then nil
  when 1 then values.first
  else        values
  end
end