class Rspec::Core::Formatters::BaseFormatter

def start(example_count)

is #add_behaviour
This method will only be invoked once, and the next one to be invoked

formatters that need to provide progress on feedback (graphical ones)
they have all been collected. This can be useful for special
This method is invoked before any examples are run, right after 
def start(example_count)
  @example_count = example_count
end