HeartButton.swift

import UIKit

class HeartButton: UIButton {
  
  private let unlikedImage = UIImage(named: "heart_empty")
  private let likedImage = UIImage(named: "heart_filled")

  override public init(frame: CGRect) {
    super.init(frame: frame)

    setImage(unlikedImage, for: .normal)
  }
  
  required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }
}