gistfile1.txt

class Foo
  def self.versions(a)
    @@versions = a
  end

  def build_versions
    @@versions.each do |key,value|
      self.instance_eval &value
    end
  end

  def hello(name,age)
    puts "Hello #{name} and you are #{age} old"
  end
end

class Bar < Foo
  versions(
    :name => proc { hello('hemant',30) },
    :age  => proc { hello('Kiran',28) }
  )
end

a = Bar.new()
a.build_versions()