Objective-C code that helps you assign [NSNull null]
within RubyMotion.
$ git clone git@github.com:colinta/nsnulldammit vendor/nsnulldammit
app.vendor_project('vendor/nsnulldammit/', :static)
dict = {}
array = [1,2,3]
person = Person.new
dict.setToNull('key') # dict['key'] = NSNull.null
array.setIndexToNull(1) # array[1] = NSNull.null
array.appendNull # array << NSNull.null
person.setToNull('email') # person.email = NSNull.null