title: Overload resolution ambiguity: String Builder kotlin?
body: <p>I am using stringbuilder to concatenate strings</p>
  
  <p>I get the error</p>
  
  <pre><code>Overload resolution ambiguity: 
  public open fun append(p0: StringBuffer?): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Any?): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Boolean): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Char): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: CharArray!): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: CharSequence?): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Double): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Float): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Int): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: Long): StringBuilder defined in java.lang.StringBuilder
  public open fun append(p0: String?): StringBuilder defined in java.lang.StringBuilder
  </code></pre>
  
  <p>This is my function</p>
  
  <pre><code>fun getCannotPurchaseItemMsg(domain: String?): String? {
      val builder = StringBuilder()
      if (localizationResult?.contentNotEnabledMessagePrefix != null)
          builder.append(localizationResult?.contentNotEnabledMessagePrefix)
      else if (genericMessages?.contentNotEnabledMessagePrefix != null)
          builder.append(genericMessages?.contentNotEnabledMessagePrefix)
      if (builder.toString().length == 0)
          return null
      builder.append(" ")
      //        builder.append(getAppCMSMain().getDomainName());
      builder.append(domain).append(" ")
      if (localizationResult?.contentNotEnabledMessageSuffix != null)
          builder.append(localizationResult?.contentNotEnabledMessageSuffix)
      else if (localizationResult?.contentNotEnabledMessageSuffix != null)
          builder.append(localizationResult?.contentNotEnabledMessageSuffix)
      return builder.toString()
  }
  </code></pre>
  
  <p>This error is being said on </p>
  
  <pre><code>builder.append(localizationResult?.contentNotEnabledMessageSuffix)
  </code></pre>
  
  <p>The string is decalred as</p>
  
  <pre><code>var contentNotEnabledMessageSuffix: String? = null
  </code></pre>
  
  <p>What is the issue here?</p>