gistfile1.rbx

class Test
  
  def method(text) 
    if block_given?
      yield "#{text} inside a block!"
    else
      puts "#{text} not in a block and just simply outputted to console."  
    end 
  end
  
end

t = Test.new

t.method("Hello") # => simply outputs the text above via puts

t.method("Hello with a block") do |text|
  puts "now my text is different: #{text}" # will output: "now my text is different: Hello with a block inside a block!"
end