simple dynamic dispatch example

disinterested_cat.rb

class DisinterestedCat
  def speak
    puts "..."
  end

  def play
    puts "...<look away>"
  end
end

fluffy = DisinterestedCat.new

fluffy.send(:speak)
  # => "..."
fluffy.send("play".to_sym)
  # => "...<look away>"

puts fluffy.respond_to?(:play)
  # => true
puts fluffy.respond_to?(:sit)
  # => false