code: public static void copy(AsciiString src, int srcIdx, ByteBuf dst, int dstIdx, int length) {
          if (isOutOfBounds(srcIdx, length, src.length())) {
              throw new IndexOutOfBoundsException("expected: " + "0 <= srcIdx(" + srcIdx + ") <= srcIdx + length("
                              + length + ") <= srcLen(" + src.length() + ')');
          }
  
          checkNotNull(dst, "dst").setBytes(dstIdx, src.array(), srcIdx + src.arrayOffset(), length);
      }
docs: Copies the content of {@code src} to a {@link ByteBuf} using {@link ByteBuf#setBytes(int, byte[], int, int)}.
  Unlike the {@link #copy(AsciiString, ByteBuf)} and {@link #copy(AsciiString, int, ByteBuf, int)} methods,
  this method do not increase a {@code writerIndex} of {@code dst} buffer.
  
  @param src the source string to copy
  @param srcIdx the starting offset of characters to copy
  @param dst the destination buffer
  @param dstIdx the starting offset in the destination buffer
  @param length the number of characters to copy