code: public static Object[] mergeNativeArrays(Object[] dst, Object[] src, int dstPosition, boolean doPowerOf2) {
  
  	if (dstPosition < 0) dstPosition = dst.length;
  
  	Object[] result = resizeIfNeeded(dst, dstPosition + src.length, doPowerOf2);
  
  	System.arraycopy(src, 0, result, dstPosition, src.length);
  
  	return result;
      }
docs: this method efficiently copy the contents of one native array into another by using
  System.arraycopy()
  
  @param dst - the array that will be modified
  @param src - the data to be copied
  @param dstPosition - pass -1 to append to the end of the dst array, or a valid position to add it
  elsewhere
  @param doPowerOf2 - if true, and the array needs to be resized, it will be resized to the next
  power of 2 size
  @return - either the original dst array if it had enough capacity, or a new array.