class Middleman::CoreExtensions::Collections::StepContext

def self.add_to_context(name, &func)
  send(:define_method, :"_internal_#{name}", &func)
end

def initialize
  @descriptors = []
end

def method_missing(name, *args, &block)
  internal = :"_internal_#{name}"
  if respond_to?(internal)
    @descriptors << send(internal, *args, &block)
  else
    super
  end
end