Common buffer operations

// scala code
object Test {
  import scala.collection.mutable.ArrayBuffer
  val buf = new ArrayBuffer[Int]()
  buf += 1
  buf += 2
  buf ++= Array(3, 4)
  buf += (5, 6)
  buf.insertAll(0, List(11, 11, 11))
  buf.insert(0, 22)
  buf.toArray
  buf -= 11 // remove the first 11
  buf.toArray
  buf.remove(1)
  buf.toArray
  buf.remove(1, 3)
  buf.toArray
  buf.trimStart(1)
  buf.trimEnd(1)
  buf.toArray
  val buf1 = buf.clone() 
  buf1.toArray
  buf.clear 
  buf.toArray
}