Google

def delete( attribute ) name = nil prefix = nil if attribute.kind_of? Attribute name = attribute.name prefix = attribute.prefix else attribute =~ Namespace::NAMESPLIT prefix, name = $1, $2 prefix = '' unless prefix end old = fetch name, nil attr = nil if old.kind_of? Hash # the supplied attribute is one of many attr = old.delete(prefix) if old.size == 1 repl = nil old.each_value{|v| repl = v} store name, repl end elsif old.nil? return @element else # the supplied attribute is a top-level one attr = old res = super(name) end @element end