title: How to combine several annotation into one in Kotlin?
body: <p>I'm trying to validate RequestBody using my custom annotations.</p>
  
  <p>With configuration below my validation works:</p>
  
  <pre><code>data class PlayerRegistration(
      @field: Email
      val email: String,
      @field: Pattern(regexp = NICK_REGEX)
      @field: Size(min = 5, max = 15)
      val nick: String,
      @field: Pattern(regexp = PASSWORD_REGEX)
      @field: Size(min = 8, max = 20)
      val password: String,
      val birthDate: LocalDate
  )
  </code></pre>
  
  <p>But when I try to sum up annotations like this:</p>
  
  <pre><code>data class PlayerRegistration(
      @field: Email
      val email: String,
      @field: ValidNick
      val nick: String,
      @field: ValidPassword
      val password: String,
      val birthDate: LocalDate
  )
  
  @Pattern(regexp = NICK_REGEX)
  @Size(min = 5, max = 15)
  @Target(AnnotationTarget.FIELD)
  private annotation class ValidNick
  
  @Pattern(regexp = EMAIL_REGEX)
  @Size(min = 8, max = 20)
  @Target(AnnotationTarget.FIELD)
  private annotation class ValidPassword
  </code></pre>
  
  <p>It doesn't work. What am I doing wrong?</p>