Attributes are in key-value form, and if there’s no value provided for an attribute, a NotAvailableValueError will be raised.
# File rss/rss.rb, line 150
def initialize(tag, value, attribute=nil)
@tag, @value, @attribute = tag, value, attribute
message = "value <#{value}> of "
message << "attribute <#{attribute}> of " if attribute
message << "tag <#{tag}> is not available."
super(message)
end