def big_classes(max_size=1.megabytes)
      return @big_classes if @big_classes
      @big_classes = {}
      ObjectInformation.where(:group_instance_id => self.id, :memsize.gt => max_size).all.each do |object|
        @big_classes[object.class_name] ||= {total_mem: 0, average: 0, count: 0}
        @big_classes[object.class_name][:total_mem] += object.memsize
        @big_classes[object.class_name][:count] += 1
      end
      @big_classes.each_pair do |klass, hash|
        @big_classes[klass][:average] = @big_classes[klass][:total_mem] / @big_classes[klass][:count]
      end
      @big_classes
    end
def big_classes(max_size=1.megabytes)
      return @big_classes if @big_classes
      @big_classes = {}
      ObjectInformation.where(:group_instance_id => self.id, :memsize.gt => max_size).all.each do |object|
        @big_classes[object.class_name] ||= {total_mem: 0, average: 0, count: 0}
        @big_classes[object.class_name][:total_mem] += object.memsize
        @big_classes[object.class_name][:count] += 1
      end
      @big_classes.each_pair do |klass, hash|
        @big_classes[klass][:average] = @big_classes[klass][:total_mem] / @big_classes[klass][:count]
      end
      @big_classes
    end
Return an array of hashed that contains some information about the classes that consume more than `max_size` bytess