kopylovvlad

require 'json'

module JSONable
  def to_json(*options)
    as_json(*options).to_json(*options)
  end
end

class Tag
  attr_reader :title

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class SlackLogger
  def initialize(message)
    @message = message
  end
  def sending
    puts 'we sending message to Slack'
  end
end
class EmailLogger
  def initialize(message)

kopylovvlad

# some classes
class SlackLogger
  def initialize(message)
    @message = message
  end
  def sending
    puts 'we are sending message to Slack'
  end
end
class EmailLogger

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class Database
  @@instance = Database.new

  def self.instance
    return @@instance
  end

  private_class_method :new
end

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class Robot
  attr_reader :model_name, :id, :release_date
  def initialize(model_name:, id:, release_date:)
    @model_name = model_name
    @id = id
    @release_date = release_date
  end
end

class RobotFirstDecorator < SimpleDelegator

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module SpamFilter
  def self.is_spam?(msg)
    # magic code is here
  end
end

# == Schema Information
#
# Table name: comments
#

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module TagCreator
  def self.render(tag_object)
    return '' if tag_object.nil?
    return tag_object if tag_object.is_a?(::String) or tag_object.is_a?(::Integer)

    str = "<#{tag_object.tag_name}>"
    str += TagCreator.render(tag_object.content)
    str += "</#{tag_object.tag_name}>"
    str
  end

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require 'singleton'

class Employee
  attr_accessor :name, :number, :address

  def initialize(args = {})
    @name = args[:name]
    @number = args[:number]
    @address = args[:address]
  end

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class AbstractLeaf
  def initialize; end
  def size
    raise 'Called abstract method: size'
  end
end

class AbstractComposite
  attr_reader :subgroup
  def initialize(args = {})

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module Subject
  def initialize
    @observers = []
  end

  def add_observer(event_type, observer)
    @observers << { event_type: event_type, observer: observer }
  end

  def delete_observer(event_type, observer)