Add a part to a
multipart message, with the given content-type. The part itself is yielded to
the block so that other properties (charset, body, headers, etc.) can be
set on it.
# File actionmailer/lib/action_mailer/part_container.rb, line 25
def part(params)
params = {:content_type => params} if String === params
part = Part.new(params)
yield part if block_given?
@parts << part
end
