def for *classes, &proc
      classes.each { |receiver_class| ForClassContext.new(self, receiver_class).instance_eval &proc }
    end
def for *classes, &proc
      classes.each { |receiver_class| ForClassContext.new(self, receiver_class).instance_eval &proc }
    end
def for * classes , & proc classes . each { | receiver_class | ForClassContext . new ( self , receiver_class ) . instance_eval proc } end
For class context
For class context