code: @IgnoreJRERequirement
      private CharSequence getSubSequence(CharBuffer cb, int start, int end) {
          return cb.subSequence(start, end);
      }
docs: Get sub sequence of buffer.
  
  This method avoids error in java-api-check.
  animal-sniffer is confused by the signature of CharBuffer.subSequence()
  due to declaration of this method has been changed since Java7.
  (abstract -> non-abstract)
  
  @param cb a buffer
  @param start start of sub sequence
  @param end end of sub sequence
  @return sub sequence.