code: public int find(@NotNull byte[] bytes, int off, int len) {
  		assert !isRecycled() : "Attempt to use recycled bytebuf";
  		L:
  		for (int pos = head; pos <= tail - len; pos++) {
  			for (int i = 0; i < len; i++) {
  				if (array[pos + i] != bytes[off + i]) {
  					continue L;
  				}
  			}
  			return pos;
  		}
  		return -1;
  	}
docs: Finds the given byte array in the {@link #array} and returns its position.
  This {@link ByteBuf} must be not recycled.
  
  @param bytes the byte array which is to be found in the {@link #array}
  @param off offset in the byte array
  @param len amount of the bytes to be found
  @return the position of byte array in the {@link #array}. If the byte wasn't found,
  returns -1